drYad hanging shelter
When you’re young and eager and tough, and the weather isn’t too perishingly cold, you do without a mattress. I did so all through the six months of my California walk (except for the first few days when, to cushion the shock of changing from soft city life, I carried a cheap plastic air mattress that I didn’t expect to last long, and which didn’t). I soon got used to sleeping with my mummy bag directly on all kinds of hard ground, but I often padded the bag inside with a sweater or other clothes. On that trip temperatures rarely fell more than a degree or two below freezing, though on one occasion I slept on stones at 25°F. (That night I had a floored tent and a few sheets of newspaper, which make a very useful emergency insulator.)
But failing to use some kind of insulation under your sleeping bag (unless it’s a foam bag) is, in all but consistently hot weather, grossly inefficient: your weight so compresses the down or synthetic directly beneath you that its air-holding and warmth-conserving property is cut almost to zero. And even when cold is no problem you’re liable to find that if you’ve grown used to an ordinary bed, the change to unpadded bag-on-the-ground ruins your sleep for at least a few nights. This reduces both your efficiency and enjoyment, and the saving in weight just isn’t worth it—unless you can be sure of finding soft, dry sand for a bed. Then all you need is a couple of wriggles to dig shallow depressions for shoulders and rump, and you’ve got yourself a comfortable sleep.
The traditional woodsman and Boy Scout routine was to build a mattress from natural materials: soft and pliable bough tips, or moss or thick grass. On the California walk I did for a while use branches from desert creosote bushes. But in today’s heavily traveled backcountry camping areas the cutting of plant life is not merely illegal but downright immoral—an atrocity committed only by the sort of feebleminded citizen who scatters empty beer cans along our roadsides. Besides, the method is inefficient. Even when you can find suitable materials, you waste time in preparing a bed. And the bed is rarely as warm or comfortable as any of the modern lightweight pads or mattresses.
For perhaps 20 years the standard equipment under almost all conditions was an air mattress. These traditional devices have now almost, but not quite, disappeared from mountain shops. I still use one occasionally, though, when I judge the night won’t be cold enough to make sub-sleeping-bag insulation a major problem but weight, or even just comfort, might be; when I think I might need it for a river crossing; when bulk poses a load problem; or if I want to spend a lot of time sitting and reading or writing, and like hell fancy the idea of an easy chair (though for a more comfortable chair, see this page).
If you decide you want an air mattress for some reason, avoid at all costs—unless you want it only for a night or two—one of the cheap, thin, plastic jobs. They puncture and tear almost without provocation, and often don’t get the chance to do either before a seam pulls open. Coated nylon does much better.
An air mattress amplifies the efficiency of your sleeping bag by keeping a cushion of air between it and the ground. The air can circulate within the tubes, though, and therefore passes heat by convection from warm body to cold ground—and especially to snow. But an air mattress also neutralizes the sharpest stones, supports your body luxuriously at all the right places, converts into an easy chair, and will if necessary float you and your pack across a river (this page). It also gets punctures.
An offshoot is the down-filled air mat (DAM). This unlikely device by Stephenson-Warmlite is an attempt to combine the sink-in comfort of an air mattress with the much greater insulation of small, trapped air pockets. A box-baffled, urethane-coated nylon shell, fitted with an air valve, is filled with goose down, as in a sleeping bag or jacket. The great gain compared with a self-inflating pad (see below) is reduced bulk for packing. But in case of a puncture you lose the backup of a conventional foam pad. And because your breath would soon soak the down you must inflate the DAM with a short plastic tube attached to a special sleeping-bag stuff sack that acts as pump. In addition, because DAMs are made in special conformations to fit specific Stephenson sleeping bags, they’re damned expensive: $140. All are 3 inches thick. Weights: from 1 lb. 4 oz. to 1 lb. 9 oz.
Foam pads succeeded air mattresses as king of the backcountry underbed, and they ruled for perhaps a decade.*10
Still air trapped in small enough chambers—less than (¼-inch diameter—forms an excellent barrier to heat transfer, and foam pads hold the air in just such small chambers and therefore insulate far better than air mattresses. They also tend to be lighter and cheaper—and puncture-immune. But they’re bulkier, and most of them are far less comfortable—except on snow or sand or a deep pile of leaves or other soft underlayer. In addition, they make inferior chairs and will help you precious little on river crossings. On balance, though, they proved better than air mattresses and superseded them for general backpacking, especially in cold places. For years no one in his right mind has carried an air mattress for snow work.
For 20 years now, you’ve been able, under almost all conditions, to have the best of both worlds.
It’s very rare for a new piece of backpacking equipment to sweep aside, almost overnight, all the oldies. But Cascade Designs’s Therm-a-Rest mattress virtually pulled it off. A Therm-a-Rest—or one of the later competitors—is at least as comfortable as an air mattress and insulates better than most pads. The idea is simple: an open-cell foam pad that is covered with a tough, waterproof, airtight nylon twill cover bonded to the foam. A valve at one corner enables you to control the air pressure in the foam’s spaces. To deflate for packing you roll the mattress on a flat surface or your thighs, then close the valve. The mattress remains rolled and is reasonably compact. To inflate you simply open the valve: the mattress will slowly unroll, and within a few minutes—the time needed to erect a tent, say—it’s ready for use. You can simply close the valve or you can—as I almost always do—blow more air in and then close the valve. Inflated that way, the mattress is more comfortable as well as a more efficient insulator. Rather to my surprise, I find that the harder it’s inflated, the more comfortable it is. But you can experiment and then minister to your personal druthers.
Punctures occur only rarely (full instructions for repair come with each mattress, and there’s now a repair kit—Hot Bond, $5—said to be good); even a punctured Therm-a-Rest is still a serviceable open-cell foam pad (for open- and closed-cell pads, see this page). Faulty valves can be replaced fairly simply (spares, $5). It’s my experience, widely shared, that if you treat your Therm-a-Rest with anything less than brutality it will give good service. It is very well made and the makers stand sturdily behind their product—even, sometimes, beyond the two-year warranty.
I suspect that a Therm-a-Rest might even fill the special role of air mattress as flotation device for you or your pack (this page)—though if you ever got water in that open-cell foam…
Naturally, all this joy does not come cheap—in ounces or dollars.
CHIP: But, like a good sleeping bag, the cost is reasonable if you reckon the years of good service. I bought my first Therm-a-Rest mattress, an orange ¾-length, in 1980. It cost me $39—a vicious bite at the time. But divide that by the 21 years since and you get $1.86 per year for a decent night’s sleep. That’s quite a bit less than if I bought a new, cheap air mattress every year. My original Therm-a-Rest does have drawbacks. The nylon shell is slippery. I sprayed and resprayed it with Slip Fix, making it look as if I’d blown my nose on it 10,000 times, and even the anti-slip coating has grown polished with use. In 1987, I punctured it once, mysteriously, dead center, and applied a neat patch from the kit. So, in hard and constant use, that’s 0.05 punctures per year. About 1989, the original brass valve crapped out so I replaced it with a mitten-operable plastic one. All my pad lacks is a name.
The new Therm-a-Rest pads are topped with nonslip polyester and undergirded with a coated nylon oxford. The valve is long-lasting plastic. The repair kit is likewise improved, with a heat-bonded patch (you use a pan of boiling water) rather than the old glue-on type.*11
There are four Therm-a-Rest series: Luxury, Performance, Classic, and Discovery. The first three come in full- or ¾-length. But some full-length pads, at 77 inches, are fuller than others, at 72. The ¾-length pads are 56 inches or 47. Any pad with “Camp” in the title is both longer and wider (25 inches versus 20). Except for the CampLite I’m not listing the Camp-width pads, because they’re on the heavy side for backpacking.
The Luxury Edition pads (full: 2 lbs. 5 oz., $110; ¾-length: 1 lb. 9 oz., $82) have round, widthwise channels in the foam, for lightness and also cushy butt-hugging thickness (2 inches). Topped with Softknit fabric, these verge on the indecent—if you have hidebound notions of roughing it, that is. But if you’re heavy and bony, tending to bottom-out on regular pads, this one’s the ticket. Just don’t crow too loud, or your significant other will snag it (mine did).
The Performance Series is filled with LiteFoam, which is cut vertically with overlapping slots and then stretched across the width. The 1.6-inch-thick CampLite is both longer (77 inches) and wider (25 inches) than the standard 72-by-20-inch pad, while only weighing 4 oz. more (full: 2 lbs. 12 oz., $80; ¾-length: 1 lb. 15 oz., $70). After Linda selected my new Luxury pad for her personal suite, I adopted the 1-inch-thick UltraLite (full: 1 lb. 8 oz., $70; ¾-length: 1 lb., $54). Blown up taut, it gives me just enough flotation for comfort and packs beautifully—the ¾-length size rolls to a 4-inch diameter and is 10.5 inches long. In summer, I stick with ¾-length pads. In winter, I formerly used a ¾ pad and wadded up extra clothes under my feet. But, with the advent of ultralight models, I’ve switched to a full-length pad for snow camping, with a reflective layer beneath (this page).
The Therma-a-Rest Classic Series is the old reliable Standard, 1.5 inches thick with improved foam and a nonslip woodsy green top (full: 2 lbs. 8 oz., $65; ¾-length, 1 lb. 9 oz., $50). The Discovery Series Explorer weighs the same, has the same warranty, and costs less (full: $50; ¾-length, $40). A combination cover with straps and pillow sleeve called the Therm-a-Wrap has just risen from the waves.
I visited Cascade Designs in Seattle and watched the birth of a Therm-a-Rest UltraLite pad—or a whole herd of them, actually—laminated, pressed, and bonded. Kitty Graham, my guide, had two dogs curled up by her desk—it seemed like a pleasant place to work.
Other makers are trying hard to get into the bedroom-on-your-back. Artiach, a Spanish company, makes a pad covered in a glossy, nonslip polyester called the Skin Mat. The covering does feel disconcertingly like skin, though not human skin. It’s dark gray and crinkled, like those 1960s B-movie Martians that scared my smaller self. The Skin Mat’s not scary, though. Instead, it rolls up compactly and has a light protective cover. As pads go, it’s not bad, though it doesn’t fully inflate without some puffing and I did pinhole it first time out. But I repaired it by rubbing cement over the hole—didn’t need a patch. I have a regular 63-inch midlength pad (1.5 inches thick, 1 lb. 14 oz., $64). I’ve been using this as my winter pad, for several reasons. The length works out nicely, with a fat makeshift pillow of fleece. It’s rather thin-skinned, but snow covers the world’s horny hide. And there’s nonslip “skin” on both sides of the pad, so it doesn’t skate around on the Reflectix sheet I use underneath (which coated nylon does most annoyingly). Artiach also has a more conventional Confort Mat Series and a Compact Mat Series, all in long, ¾-length, and the distinctive 63-inch midlength size. Weights are from 1 lb. 5 oz. to 5 lbs. 5 oz. and prices range from $49 to $98.
Stearns takes a different tack with the Ergo Mat Series. The open-cell foam isn’t bonded to the casing. This means you can puff it up a bit extra and get the full floating-air effect, with enough foam to keep you from bottoming, shouldering, hipping, or heeling out. (My friend Paco, aka Jack’s Plastic Welding, has made river runner’s pads this way for years, and they’re the catfish’s pajamas, though a bit hefty for backpacking.) Anyhow, the full-length Ergo Mat’s tapered, mummy shape has three segments so you can vary the softness and thickness from back to bum to legs. There’s also an inflatable, foamless pillow. Once you get it right, it’s comfortable for the weight and bulk—combining the virtues of a self-inflater and a well-designed air mattress. The drawbacks are three plastic flap valves, but they’re located so that rolling up the pad exhausts the air and then more or less automatically closes each valve in turn. Two snap-on straps are included. The pad I tried a few years ago, the Ergo Mat Long (77 by 22 by 1.5 inches, 1 lb. 10 oz., $54) had a somewhat slithery top cover, though the current catalog lists all variations as having nonslip fabric.
Other semi-aerated pad purveyors are Backcountry Designs, Coleman, Mountain Equipment Co-op, Paramount Outfitters, Slumberjack, Sunny Rec, and Wenzel.
Before the trip, open the valve, let the pad uncrimp, and then blow it up tight and leave it overnight, to let the foam expand. (If it’s limp the next morning, take it back to the store.) To keep your pad in good shape, store it with the valve open so the foam doesn’t lose its bounce. To pack it, roll it once to get the air out, then unroll, fold double along the length, and re-roll for storage inside your pack. Or roll it up once and cover it with some sort of bag or sheath for transport outside your pack. Lashing a pad unprotected to the top or rear of your pack exposes it to sharp stubs, thorns, rock crystals, etc. Keep mosquito repellents with DEET (diethyl-whatever) way away: it melts the urethane used to coat (i.e., hold air inside) synthetic fabrics. That is, power lounging after applying bug dope can ruin your day (and night). All the generic finger wags about UV apply. The trick is not to sacrifice your enjoyment to preservation: your pad need not outlive you.
Pads that (intentionally) don’t inflate
COLIN: Naturally, not everyone will want a Therm-a-Rest. Some people are, for good, bad, or indifferent reasons, wedded to foam pads. These can be lighter and less bulky, not to mention cheaper. And cost may be a crucial factor, especially if you backpack only rarely.
Closed-cell foam pads have impermeable surfaces and trap tiny air pockets almost permanently. They therefore insulate extremely well and are mostly waterproof. But they compress very little and, although thin (⅜ through ½ inch), are bulky to pack. When a pad is new, indentations quickly disappear; but with age it becomes, like people, less resilient. And severe cold makes some foam stiff and brittle. The thinness and incompressibility mean that closed-cell pads do not cushion you well; but comfort can be increased—at considerable cost in weight and bulk—by laminating sheets together. Pads come in various hip- or full-length sizes, or in sheets you can cut to suit.
Most early closed-cell pads were Ensolite. It has been improved and joined by others, and we now have a spectrum of pads in a wide range of sizes, weights, costs, and resistance to cold and abrasion. For a few current spectrum points, see below. Others exist. More will assuredly follow—and wax and wane with the passing moons.
CHIP: Among the determined users of closed-cell pads are those who bivouac on puncture-rich ground: in talus caves, on desert pavement, or under snaggly scrub. (The more sybaritic members of the tribe also slip a ¾-length self-inflater inside the bivouac sack.) Generic single-layer slabs can be scooped up in discount stores for $5 to $10. Those in backpacking shops range from $10 to $20. Black Ensolite, which resists cracking in cold weather, comes in ½- and ¾-inch thicknesses and 6-foot lengths, for $30 to $45.
Wildly popular are two closed-cell pads from Cascade Designs. The Ridge Rest goes through a special press that leaves crosswise corrugations in the foam. This renders the pad slightly more compressible under body weight, for comfort. There’s probably no one in the developed world who hasn’t seen one of these, if only by the side of a highway, blown off the roof rack of some hapless soul. They’re superb, as 3-season pads, and I use one regularly. But winter’s a different story. If you don’t get every bit of snow off them before going to sleep, or if there’s frost falling from the inside of the tent, your body heat melts it and the neat little channels channelize it to the lowest point: right under your sleeping bag. The Ridge Rest Deluxe (two-tone purple and metallic green) is 72 by 20 by ¾ inches and 1 lb. 2 oz. for $29. The Ridge Rest Regular is ⅝ inch thick, 14 oz., and $20, with a ¾-length version a mere 9 oz. and $15.
The Cascade Designs Z-Rest goes into a different press, and comes out in a pattern you could call egg-crate (for hummingbird eggs). Rather than rolling, it folds up accordion-fashion, with the little eggules nesting into one another. This makes for compact, if rectilinear, packing. Even though it appears lighter, it weighs a bit more than the regular Ridge Rest: the 72-inch Z-Rest weighs 1 lb. and runs $30, while the ¾ size is 11 oz. and $24. Lighter people rave about how comfortable the Z-pads are, while bony heavyweights (me) tend to flatten the eggules at key points, and thus prefer the Ridge Rest. When I visited Cascade Designs, they were working on a new, ultraresilient, top-secret formula for Z-Rest foam. The enemies of these pads are solvents and heat: don’t leave them under the rear window of a parked hatchback. A tangential use is to stiffen up the mattresses in Third World hotels or student rentals.
COLIN: Open-cell foam pads compress easily and are therefore more comfortable than Ensolite and its cousins. But to achieve the same insulation they must be about three times as thick (normal range, 1½ to 2½ inches). So they’re bulkier, heavier, and more expensive. The bulkiness is more apparent than real: stuffed hard into a packbag, they compress halfway well. Open foam is often corrugated, in “egg-crate” or zigzag form, to increase comfort with minimum additional weight.
Because the open-cell structure soaks up water, the pads mostly come with covers—coated waterproof nylon underneath, with a nonslip blend on top to reduce slipperiness and permit perspiration to dissipate. A pleated pocket at the head of the cover may offer holding space for whatever pillow you choose to inject (this page). Before the advent of the Therm-a-Rest, I used a Sierra Designs version of such a pad for years under most conditions except snow and found it as warm and trouble-free as Ensolite and almost as comfortable as an air mattress. A Georgia reader suggests a cheap, do-it-yourself covered pad: open-cell foam, 25½ inches wide, 1 or 1½ inches thick, with two industrial-strength plastic garbage bags slipped over opposite ends, joined amidships with duct tape, and punctured at one end (for air escape and easier packing) with slits placed at ½-inch intervals.
Meanwhile, evolution pads on.
CHIP: Mountain Hardwear has a new series of tapered pads, 1.6 to 2.4 inches thick, in 50-, 60-, 72-, and 77-inch lengths. Weights range from 1 lb. 12 oz. to 4 lbs. 6 oz., and prices from $42 to $89. Not inflatable—by any normal means at least—they have wiggly open-cell foam laminated to a sheet of closed-cell foam and nonslip covers with nice pillow sleeves. Everything I’ve seen from the Mountain Hardwear folks has been top-notch, and early reviews on these pads are good, except for the rolled-up size, which is bulkier than that of a self-inflater.
Reflectix insulation is grand stuff: thin aluminum foil on both sides, bonded to a 5/16-inch sheet of bubble wrap. I got a roll to insulate my workshop, and liked the looks of it. So I cut off a 74-inch piece to take snow camping. The insulated part is 22 inches wide, with a 1-inch stapling strip on either edge. My pad liner weighs 10.5 oz. (or 1.7 oz. per foot). Camping in February, I noticed that I hadn’t melted out my usual body trough in the snow under the tent floor. That’s a first, since I radiate heat like a fresh-caught meteorite. The bubble wrap gives it minor effectiveness as padding: on snow, hardpersons can punch out hip and shoulder recesses and use Reflectix alone. It’s slickery under sleeping bags, though, and knees and elbows tend to pop a few bubbles each time you roll, so the life span is limited. But mine has survived its third winter. Reflectix and similar products can be found in eco-solar-type catalogs, or at the local home center. A 25-foot roll (four full-length pads) costs $25.
Last and most curious is a hybrid sleeping pad/chaise, the subinflationary PowerLounger, at 54 by 17.5 by ½ inches. The core is foam, while the nonslip cover has wing straps that elevate the upper third into a nearinstantaneous backrest. The PowerLounger (1 lb. 14 oz., $51) is built by Crazy Creek Products, who also originated the backpacker’s chair.
as Variety might put it, now do boffo biz with hike-happy hordes. Since Crazy Creek ranks first in time, let’s take them as somewhat representative. There are two main types. The fabric and foam chair (no inflation) buckets around your buttocks in a way that’s at first disconcerting. But once you get the way of it, you can be comfortable indeed. The Crazy Creek original weighs 22 oz. and costs $37. Variants exist for canoes, stadiums, and other presently unimaginable spots. I saw a young couple using one in a futile attempt to ensconce their unhappy child on the back of an unhappier llama. The second sort is a fabric shell, with wands or stays, that warps a self-inflating pad into chairlike form. Crazy Creek makes the ThermaLounger in various widths and lengths from Mini to Camp, and weights from 15 oz. to 1 lb. 14 oz. Not only must the width be compatible with your pad, but length figures in too.
In a moment of weakness I got a Therm-a-Rest Lite 20 Easy Chair, in a color called Grape. (Hail to thee, blithe nylon—grape thou never wert!) Despite every intention of testing it rigorously, I haven’t unwrapped it yet. It slumbers, vivid, beneath its plastic shroud. My fear is, I guess, that I’ll head off on a walking trip only to spend more time lounging than walking. In any event, Cascade Designs has Easy Chairs to fit all of their pads (except the Z-Rest). As do most other pad-forming entities.*12
I do rely, especially after lugging a heavy winter pack and being storm-cooped in a tent, on a self-supporting device. But it’s not a chair. It’s a construct of webbing, buckles, and modest pads called, in fact, the Nada-Chair (9.5 oz., $49). The back support, 6 by 20 inches, is crossed by 2-inch webbing loops that slip down over your knees and then buckle together, midthigh. It works the same way as a Crazy Creek Chair, but discreetly. You can’t plunk down in it. You have to sit in a conscious way. But you can get out of it more easily. I find it pleasanter, on the whole, than a butt-enveloping slab of nylon. And it’s certainly a lot lighter. Since you wear it rather than sit in it, it also works as a back brace for pounding a keyboard, as I’m doing now.
I’m not sure whether doubling up my sleeping pad in winter accords—philosophically at least—with my stringency in the matter of chairs. An eminent book reviewer once observed: “There is something of the anchorite in Rawlins.”
I leave it up to you.
COLIN: A reader once wrote from Liberia that he often used his army hammock from Vietnam for backpacking, “with no regrets…only a few reservations.” Now, most people shy away from the idea of sleeping in a hammock, especially after a long day with a heavy load. I certainly do. But you may not. And I guess a light hammock can be useful as a bed if you want to keep cool (air all around you) in a place as hot as Liberia; if the ground, every place, is soaking wet; if you’re petrified beyond sleep by the thought of rattlesnakes or scorpions or other things that might go chomp in the night; if the local ground insects are a ravenously hungry host; or if you’re an old-style sailor, landlubbering but pining. Other suggested uses: for slinging food and gear from trees, high above the ground, as protection against flood, bears, and other invaders; for rest, not sleep, at a base camp; and, with poles, as an emergency stretcher.
My Liberian correspondent’s hammock seemed to be of some solid fabric: he didn’t like or trust “the net-type sold for packers.” But sold they are—or at least offered: knotless synthetic-mesh jobs described as rolling into “a pocket sized ball” and damn nearly doing so (main body 32 by 72 inches, 12 oz., $15). Also sometimes seen: a Mayan Indian design, “made of miles of 100% pure cotton lace, hand woven and hand tied…so big and strong it’ll sleep three adults…. Easy to care for, will last and last” (10 by 11 feet, 3¼ lbs., $60). A selection of Mayan handwoven net hammocks and Brazilian cloth ones can be bought from a Boulder, Colorado, outfit called Hangouts.
CHIP: My uncle Sid, who spent an adventurous decade in South America, returned with a tribal hammock-for-two in which he’d slept regularly. According to him, the Indians, who practically live in their hammocks, bed down more or less crosswise. This greatly lessens the fundamental droop.
Two nylon models that I have actually seen and briefly occupied are the Blue Ridge Camping Hammock (4 lbs. 4 oz., $172, from Lawson Hammocks), which has two aluminum hoops to support the netting and fly sheet; and the Jungle Hammock (4 lbs. 3 oz., $169, from Clark Outdoor Products), which eschews hoops and uses separate rigging points for hammock and fly (four altogether). The Treeboat Hammock (3 lbs. 12 oz., $115), which I’ve heard about but haven’t seen, is made by New Tribe of Grants Pass, Oregon. It has four-point web rigging with raindrip-stopping rings at each corner and slip-in fiberglass battens. For cool nights, a Quallofil underside is 2 lbs. and $55, while mosquito net runs 15 oz. and $40. The Treeboat two-hoop rainfly is 12 oz. and $70, while a three-hoop tent top with zip doors is 2 lbs. 7 oz. and $100. The New Tribe catalog has a vast assortment of tree-scaling gear, including hardware, cordage, shot pouches, special arrows (for reaching extra-high branches), and books like The Tree Climber’s Companion by Jeff Jepson ($10.50) and Recreational Tree Climbing by Dick Flowers ($7.50).
Unfortunately, any bed that forms a catenary curve plays absolute hell with my back: I can’t sleep, and the next morning can barely walk. Which rules out the army/navy/marine-surplus models (and private variations) for me.
But hanging one’s bed from a tree does have a certain appeal. One April in southeast Alaska, I was looking for deer and brown bears with a biologically inclined friend. After boating to a snowcapped island, we walked for hours through a dank forest, clambering over roots and down trunks, all humped and festooned with soggy moss. The fact that I could scarcely walk, let alone run, on such stuff, along with the idea of horse-size bears emerging ravenous from their dens, made me mildly uneasy. There were occasional openings, called muskegs, nicely cushioned by organic muck, but our feet pressed down into groundwater at every step (imagine a floating sponge). There wasn’t a nice dry flat patch of mineral dirt for miles. The only half-decent place I could see to sleep was on bedrock points, lashed by waves, or on pebbly beaches above the tidemark. As I was pondering this aloud, my friend pointed out the bear trail that paralleled the beach, so well traveled that each pawprint was deeply indented. “Lots of edible goodies wash up, so the bears patrol,” he said. “Or at least the hungry ones do.”
“So, uhhh, Nels—where do you sleep out here?”
“On my skiff, anchored out in that little cove.”
For the skiffless, whether afoot or a-kayak, a ripe possibility is the Dryad DT 100 Suspended Shelter by the Canadian firm Terrelogic (7 lbs. 5 oz., $350). The photos in their brochure intrigued me, showing the Dryad hung between mangroves on an islet with no sand whatsoever, just interlaced roots. Another showed it 20 feet up (well out of claw range), hung from a single point. On a hike last spring down a narrow canyon, with the trail shelved on a timbered slope above a thundering creek, I’d thought: What a gorgeous place to camp, if you could just roost in a fir.
So I tested a Dryad (they render it drYad, which could conceivably be read as Dr. Yad. I do grow weary of strangely capitalized words). Picture a double-wall tent with a floor you can trust. The suspension is quite good—the floor, with tapered ends, is framed by fat aluminum tubing that plinks together with shock cord.
drYad hanging shelter
When you get it plugged together, a lengthwise nonstretch Dacron strap reefs it tight. Suspended from eight lengths of nylon cord connected to thick webbing loops, the floor is level, tight, and distinctly more habitable than a droopy-ass hammock. In cool weather you’d want an insulating pad, or better, Reflectix insulation (this page) trimmed to fit the floor.
My first night out was chill: 20°F. Even with the fly partly unzipped on both sides, there was condensation and frost. By morning the floor and the bottom of my sleeping bag were wet. Forests, the natural habitat of dryads, are both more humid and more still than open sites, so venting is crucial.*13 Double sliders on the door zips would help, and so would an overlap vent at the head. The rainfly could be made of a breathable laminate, tacking on further cost. Of course, in smiling weather, you can roll the rainfly up on one side or both, and lounge like a peeled banana on your airy, screened-in cot.
The built-in backrest was a surprise, adding great comfort for little weight. From a compact tuck it slips down two of the suspending cords. I also discovered that you can pluck bass-viol notes on the cords (the tone is quite good, for a tent). On my second—and considerably warmer—night out I rolled up the rainfly, plucked the cords, and sang “Bye-bye Blackbird” while rocking gently.
The Dryad is a camper’s rig. Hard-core climbers are best served by a single-point porta-ledge and matching fly (Terrelogic makes one, the DT 200). But most climbers’ ledges, while technologically awesome, are two or three times the weight of a tent and when folded are over 40 inches long. The Dryad, on the other hand, is sort of packable—once you get the hang of it. The frame disarticulates while remaining in its sheath, and the whole assemblage stuffs loosely into a sack that’s 26 by 9 inches. Fearing punctures, I used some emery cloth on the edgier parts of the frame, and am looking at further unauthorized (or maybe “author-ized” is the perfect word here) changes, so that I can pack the frame separately.
I’d rate the whole concept as promising. In steep, forested country, it could be a godsend. For casual use, I’d rig the thing close to the ground.
To rig from one point, on high, you need slings and an extra-cost spreader bar. Most trekking poles are too short—a 5-foot span is needed. (You also need a tether or two, to keep it from swinging or spinning—unless you enjoy that.) I had to build a 7075-aluminum eave-stretcher pole, having snapped the original fiberglass one during a complex maneuver I’d rather not describe.*14
If you need (or want) to suspend your bed more than a few feet off the deck, consult a book on big-wall climbing for relevant details and precautions. Get real carabiners (not those little keyholders) or steel rapid-links and use high-strength slings or cord. A safety harness and a pair of ascenders with etriers (stepladders of nylon webbing) and/or empirical knowledge of Prusik-loop technique is essential. Suspended camping needs to be practiced, since the inexorable effect of gravity can nudge the usual mishaps toward disaster.
Besides eco-activist tree sitters, the other prong of development for hanging shelters has been biologists who work in forest canopies. Dr. Nalini Nadkarni, of Evergreen State College in Olympia, Washington, the president of the International Canopy Network (www.evergreen.edu/ican [website is no longer active]), kindly gave me several leads. An article on safe rigging, with a diagram of a line-tossing apparatus that grafts a Wrist Rocket slingshot onto a spinning reel, is “An Improved Canopy Access Technique,” by Gabriel F. Tucker and John R. Powell, Northern Journal of Applied Forestry, 8 (1), March 1991. Tree-climbing gear is available from Forestry Suppliers and from New Tribe.
Once you attain a major branch, you can rig separate slings for the shelter, keeping the main rope for ascent and descent. (In brown bear country, all anchors should be out of reach—the bear’s that is.) My third time out, I rigged the shelter high, then hauled my pack up and hung it from a branch like a swinging cupboard. After which I cooked soup on my hanging stove. Other happy adjuncts were a mesh gear loft and a Sierra Designs coffee sling.
Obviously, I’m fascinated by the whole arboreal riff, and wonder whether human evolution took a wrong swerve.
COLIN: For good reasons, we’ll consider the fundamentals of warmth retention in the Clothes Closet, not here. See The Prime Purpose of Clothes, this page, and The Fundamentals of Insulation, this page. If you can’t be bothered to check those pages, at least remember that sleeping bags, like clothes, are not to “keep the cold out,” as the old saying goes, but to conserve heat from the only available source—you; also that (although the distinction is less important than with clothes) the bag is not meant to make you as warm as possible, but to maintain thermal equilibrium—a state in which your heat production roughly balances your heat loss.
Ancient Egyptian mummy
Modern American mummy
Because the first sleeping bags clearly evolved from the idea of stitching two blankets together, they took the rectangular form of a bed. But most backpacking bags are now mummy bags—designed for human forms rather than for small upright pianos.
A few people say they feel uncomfortably confined in mummy bags. Claustrophobics may certainly face difficulties; but if you’ve given mummies a fair trial and just cannot get used to any real or imagined constriction, you don’t necessarily have to put up with the inefficiencies of the old rectangular piano-envelope. Although most backpacking bags are now distinctly form-fitting (in spite of a trend away from extreme sheathing), the catalogs still offer a continuum ranging from slim through mesomorphic to downright obese—some of these are tapered but unshaped—as well as old-style rectangular. Take your well-pondered pick. But remember that each size up means marginally greater weight and bulk. And, worse, that your body has to warm, all night long, a marginally greater volume of contained air.
CHIP: Between the strictly rectilinear and the infidel mummy lies a zone of compromise, known (depending on where you start) as either semi-rectangular or modified-mummy. Sensible persons once called these “barrel-shaped” bags, a term that now refers only to those without a permanently attached hood. The modified-mummy bags are tapered at head and foot, but not so closely as to be in any wise confining. But the enduring problem with all mummy bags is that real mummies, being dead, lie still on their backs. While backpackers, after a day of strenuous travel, don’t.
A significant change over the last decade is in the number of makers offering a line of sleeping bags designed for women; at present: Eastern Mountain Sports, Kelty, Lafuma, L. L. Bean, Recreational Equipment, Rokk, Sierra Designs, Slumberjack, The North Face, and Woods Canada Ltd. In general, women’s models have more insulation in the foot and/or torso. The cut is smaller in the shoulder and roomier at the hip. Linda gives high marks to the Sierra Designs Ella, a 0°-down bag with a womanly cut, and most of the women I ask who own these bags prefer them to unisex types, but there are also complaints. One athletic female friend bought (and returned) a bag that she claims was “overwomanized,” cut not for a kayaking, trail-running woman but for a steatopygous, Willendorfian Venus.*15
Rather than offering “womanized” bags, quite a few of the best companies urge you to look carefully not just at length but also at the girth measurements at the shoulder, hip, and foot. Once you’ve measured your own girth, the rule of thumb is to add 2 inches for a close fit, 4 inches for an average fit, and 6 inches for a loose one. For instance, my ultralight Western Mountaineering Iroquois Long has a close-fitting 60-inch shoulder, a 52-inch hip, and a 38-inch foot. While the cold-weather Puma Long measures 63-54-39: ample room for a layer of fleece inside.
COLIN: Some outdoor lovers complain that mummy bags don’t leave enough room for maneuver. Opportunists may face a problem here (though a local Don Juan advises: “You’d be surprised what has been achieved. As in all games, desire is very important”). Those who plan their amatory operations in advance should note that it’s now possible to order most mummy-bag models with zippers on opposite sides so that they’ll join convivially together. And any two bags with zippers of the same kind and length will conjoin—though the hoods will face opposite ways. See also doublers, this page.
A battened-down mummy bag is a very efficient heat conserver. Old-style rectangular envelopes gave your head no protection at all, tended to leave your shoulders exposed too, and let a great deal of precious body heat escape through the bag’s wide mouth. A mummy eliminates all these faults. When you pull on the drawstrings of the hood, the fabric curls around your crown and not only protects head and shoulders but also bottles the body heat. On a really cold night you pull on the drawstrings until the opening contracts to a small hole around nose and mouth. If, like me, you prefer to sleep naked because you wake feeling fresher you may sometimes find cold air seeping down through the hole and moving uncomfortably around bare shoulders. All you need do is wrap a shirt loosely around your neck (though see Hoods, Collars, Zippers, etc., this page). But this arrangement often holds the warm air in so well that you soon find you are too hot. To reduce the inside temperature (whether you’re using a neck wrap or not) simply slacken the hood tapes a little. That will make a lot of difference: your head dissipates heat more quickly than any other part of the body (also this page). (You won’t question this statement if you’re balding fast into coot country: you’ll probably, like me, have taken to wearing a balaclava at night.) In warm weather you can leave the tapes undrawn so that the mouth of the bag remains as open as in old-style envelopes. In hot weather you can go two steps further—if you have the right kind of bag. A mummy bag designed for use only in cold weather (that is, for polar exploration, high-altitude mountaineering, and winter hunting) may have no zipper openings. So do some ultralight bags. But although an uninterrupted shell is the lightest possible design and also conserves heat the most efficiently, such a bag is now very rare. It may do its special job well but it lacks versatility. In anything but chilly weather you’re liable to find yourself sweating even though the mouth of the bag is open—with no alternative except getting partly or wholly out. A zipper opening solves the problem, and nearly all bags now come with side zippers reaching the ankles or thereabouts. The modification is not pure gain. To prevent air passage through the closed zipper it has to be faced inside with a down-filled draft flap, or the zipper zone has to be blocked with a broad extension of the main wall that snugs in tight when you close the zipper. Or there may be two full-length zippers. But even a single zipper and its flap add several ounces to the weight of a bag, and, no matter how good the blocking device, there is bound to be a slight loss in heat-conserving efficiency, but if you expect to operate at times in temperatures much above freezing, then the very great gain in versatility is well worth such minor drawbacks. Some mummy bags have zippers that open all the way around the foot so that you can ventilate your feet as well as the rest of you—and can also convert the fully opened bag into a flat though markedly tapered down cover, very useful for warm nights in the bush and cold ones back home in bed. Almost all bags now have two-way zippers: you can operate the zipper from both top and bottom, and by opening it partway at shins as well as shoulders you gain a valuable aid in the almost nightly game of adjusting your bed to suit different and changing air temperatures (this page).
Of the major sleeping-bag components—fill, shells, and liners—
The fill
is what matters most. It must hold within itself as many pockets of air as possible, to act as an insulant between the warmed inner and cold outer air, and for backpacking purposes the best material is that which does this job most efficiently for the least weight. But there are subsidiary considerations: compactibility (the packed bag should not be too bulky); fluffability (the fill must quickly expand to its open, air-trapping state after being tightly packed); efficiency when wet; even, for a few people, possible allergic effects.
Traditional down-filled bags still dominate the high-quality field. But synthetic-filled bags, which have for years been nipping at their drawstrings, continue to make technical advances, and have just about caught up. Among high-quality bag makers, a few still stick exclusively with down. But most of the big producers have added synthetic lines or even gone all-synthetic.
Down is still the most efficient fill, warmth for weight. Compressed for packing, it’s markedly less bulky than any known synthetic fill. It also fluffs back to its open, air-trapping state more quickly and totally. When not compressed it free-flows, almost like a liquid, so that it continuously and evenly fills, in a way no current synthetic will, a space that’s always changing shape—as is a compartment in a sleeping bag. In addition, a good down-filled bag should, with real care, last 10 to 15 years, against 3 to 6 years for most current synthetics. On the other hand, down is useless when wet (synthetics retain at least some insulating property, and often most of it); once wet, it is difficult-going-on-impossible to dry in the field (synthetics dry much more readily); and over a long period of continual use, as in an expedition, dirt and repeated dampness tend to reduce its loft and therefore its efficiency (though see Gore-Tex shells, this page). Down, unlike synthetics, can also generate allergies in rare individuals. It demands rather more care in maintenance. And high-quality down is now murderously expensive: on the Asian wholesale market, 600-fill is $16 per lb., 700-fill is $27, and 775 is $30, versus $6 per pound for the best current synthetics.
It’s generally accepted that the best down comes from geese (mostly from China). Much learned discourse used to occur in catalogs and mountain shops—and to some extent still does—about the virtues of white versus gray goose down (probable ultimate verdict: the difference is either nil or very little), the adulteration of down with fluff (by law, “down” must be at least 80 percent down—that is, cluster and fiber rather than quills, beaks, etc.), and even the occasional perfidious sale of mere duck down under the name of “goose” (to be labeled “goose down,” 90 percent of the clusters must actually come from geese). All new bags bear a sewn-in label showing government specifications of the fill—the American Society for Testing and Materials (ASTM) has ordained standards for down content and fill power. For some years, though, a generally accepted qualitative measure has been dampening this ongoing discourse. Fill power is not, thank God, yet another political rallying bleat: it shows the number of cubic inches an ounce of down will occupy. (The scale is not used for synthetics.) The best bag and garment makers use down with a fill power of 600, 700, or even 800, and somewhere in the blurb about their gear they will give the figure. Or should.
CHIP: Simply speaking, fill power comes from longer-tendriled, fluffier down clusters: 550-fill down has 56,000 clusters per ounce, while an ounce of 750-fill has 24,000. So good down takes up more space with the same weight of material. While there is no legal standard for fill power, the International Down and Feather Bureau recommends a test using a clear cylinder, marked with fill-power grades, with a 68.4-gram disk to gently compress the down. To reduce the variation owing to moisture content and packing methods, certified testing labs go through a five-day process of lofting and drying down samples, which means that the test batches are in optimal shape. Meanwhile, back at the plant, the down that goes into your sleeping bag is usually unconditioned. Thus, even down certified as 800-plus will give somewhat less than its rated performance after being crammed into a stuff sack and then lofted for a mere 10 minutes before you start butt-mashing it and sweating through it.
Even so, good down, in a well-made bag, has a distinctive resilience: poke it with your finger and it nudges back. Down also has amazing longevity. I have a bag made circa 1976 by Holubar of Boulder, Colorado, with 3 lbs. of down fill. I used it hard during 15 years of Forest Circusing, including six winters of snow sampling in the bitterly cold Wind River Range. I’ve washed it three times, always in special down soap, and except for a slight clumping in the hood, it’s still lofty and winter-fit after 25 years.
COLIN: Synthetic fills with fancy names and low prices have been around for years. For backpacking, I wouldn’t touch them with a walking staff. But the latest versions are a different kettle of fuzz.
Current trade names don’t matter too much: they’ll likely be gone tomorrow. But it’s worth knowing that there are three main kinds of fill presently in use and that at least one novel form lurks in the wings:
1. Long, continuous-filament fibers that cling together and are used in thick, cohesive sheets known as batts (usually rated by weight per square yard). A 5-oz. layer, uncompressed, is about 1 inch thick. Currently dominant: Polarguard (a solid-core fiber that depends on bounce for insulating capacity), Polarguard HV (with a triangular cross section that gives more insulating capacity and makes it more compressible), and Polarguard 3D (also triangular and hollow-core, but finer and softer). Other continuous-filament contenders include proprietary fibers such as Lamilite.
2. Much shorter, noncontinuous-filament fibers that can be used either in cohesive batts, much like the long-fibered layers, or in a more amorphous (i.e., chopped) form. Current trade names: Hollofil (a simple hollow-core), Hollofil II (with four channels), and Quallofil (seven channels and a silicone finish).
3. Even-shorter-fibered forms somewhat resemble down, though they may be partially bonded or come in batts. Names still being juggled include Lite Loft, Micro-loft, Primaloft, and Thermolite Extreme. Some get good reviews: Primaloft 2 is said to be “like down, but amazingly water-repellent.”*16
All three forms can be “lubricated” by spraying with silicone or other liquids to reduce the “boardlike” quality and make them feel more silky, more downlike.
It looks as if we are now not far away from a synthetic that warms and wears as efficiently as down, perhaps in a form that can also be blown into compartments. If so, it will revolutionize the sleeping-bag and down-garment field. As the R&D man for a leading maker told me years ago: “If and when we get the right synthetic it will destroy down—because of its price, because it stays warmer when wet, and because it will be easier to take care of.”
Thinsulate, a thin-fibered polyolefin/polyester synthetic insulation very popular in certain kinds of clothing (this page), did not prove suitable for sleeping bags. Ditto pile and fleece (this page), except for light, warm-weather bags. And foam bags seem to have faded into the night.
Two variations on the normal method of using fill now enjoy considerable vogue. Both appear mainly if not solely in down-filled bags.
One is simply to put 60 percent of the fill on top, 40 percent below—instead of the normal 50/50 division. Assuming a good insulating pad underneath, that makes theoretical sense: most of the heat you lose presumably escapes upward. But it seems to me that unless you tend not to move at all during the night, or always move the bag around with you when you do so (and some people apparently train themselves to do just that, even in mummy bags), then the “top” of the bag is by no means always on top. Most people lie at least part of the time on one side, and curled, so the underfilled portion tends to pull tight along your back—the most vulnerable area. That kicks a colander in the theory; but the fact is that many, perhaps most, down bags are now filled 60/40. Some, for mountaineering, even go 70/30 near the foot.
The second variation is to sew a shell with continuous baffles so that fill can be moved around, top to bottom. This is achieved by omitting the line of of blocking baffles that runs down the side of the bag opposite the zipper and keeps down from traveling, top to bottom, along transverse tubes (see next page). The idea is that in cold weather you shift down from bottom to top; in warm weather, vice versa. Satisfied users tell me it works, even when done in the dark. Frankly, I remain apprehensive of cold spots. But many bag makers now produce at least one model, usually a lightweight, built this way. Some, like Feathered Friends and Western Mountaineering, now use the down-shifting design for most of their bags, with block baffles reserved for the coldest-weather models.
The shell
Down demands one kind of internal construction; synthetics, quite another.
Down tends to move away from the points of greatest wear, notably from under your butt and shoulders (where it will be compressed and not very effective anyway) and also from the high point above your body (where, because heat rises, good insulation is vital). To minimize fill’s movement the shell is therefore divided into a series of self-contained tubes that keep the down from moving very far (see above). Because of a general tendency for down to migrate from the head toward the foot of a bag, transverse tubes work far better than longitudinal.
If tubes are made by simply stitching through the inner and outer walls of the shell you are left unprotected at the stitch-through points. If some form of batting is inserted at these points (a simple and cheap system) there’s some improvement. But not much. And except for a few ultralight models, all down sleeping bags now embody tube systems in which the tube walls—known as baffles—are constructed on one of four systems:
straight,
CHIP: These days, most top-notch bags have a differential cut (i.e., an inner layer with a smaller girth than the outer shell) with minor variations. The problem of maintaining the proper distance between the liner and shell around a tight curve—along the sides and at the head and foot—has made trapezoidal, or wedge, baffling popular. Yet another trick is for inner liners to be larger than outer shells, in what’s known as a reverse differential cut, for instance in a hood. The loose down-filled fabric liner is meant to expand around your face and forehead and seal out drafts. But one of my favorite bags is a box-quilted (that is, sewn-through) down ultralight, so when arguments rage over cut-and-bafflement, it pays to keep an open mind.
Simple transverse
Angled or chevron
As far as the visible geometry, transverse or chevron, the debate seems to have been resolved in favor of simple transverse tubes. The virtue of chevron-shaped baffles lies in preventing down shift while you sleep. But a chevron means more baffle material and longer seams, jacking up the cost. Canada’s Integral Designs makes high-quality chevron-style bags filled with Primaloft—a downy synthetic.
In good-quality down bags, the width (or spacing) of the baffles seems to have settled between 5 and 6 inches. Cold-weather bags with side-block baffles tend to use wider spacing. Several makers, Marmot for instance, vary the width, using narrower tubes through the heat-producing torso and wider ones in the heat-shedding head and foot.
The baffles themselves—invisible in a finished bag—are made of a light and usually unspecified synthetic. No-see-um mesh is often used, being tough, lightweight, and flexible. Recently, mildly elastic tricot baffles have been used by Marmot and others to add more give at the weak point—where the baffle connects to the inner shell. A high-stretch baffle first showed up on bags from Mont-Bell, a Japanese firm with elegantly functional designs that didn’t take hold in the U.S. But the idea was adopted under license by Sierra Designs. I’ve been testing one of these new bags and find that the flexy-stretchy system makes it more comfortable—for me at least.
COLIN: Long-fibered, continuous-filament synthetics, such as Polarguard, need no tubes. A single layer or combination of layers encircles the bag, with extra fill at the foot. Most such bags have quilt lines that look like baffle-tube seams, but in at least some cases they seem to be largely cosmetic: people are used to transversely sewn bags, say the makers, and demand “the down look.” Actually, the quilting of continuous-fiber synthetic to the shell increases costs and may slightly reduce insulation efficiency—though it can be argued that a floppy, unsecured shell would be a nuisance, especially on the inside. The important thing with such bags is edge stabilization, which simply means that the layers (or at least the outer layers) are sewn securely to the shell along their edges. Otherwise they tend to pull away and leave an insulation-ruining gap, and the insulation ends up twisting on itself.
Edge stabilization is equally important with shorter-fibered synthetics, such as Quallofil, when they’re used in batted layers. With such fills, quilting over the main surface is usually necessary—even when, as often happens, the batts have a lightweight scrim attached to one side to hold the material together structurally.
CHIP: Synthetic insulation is now arrayed in three main ways.
Quilting
1 .Quilting encloses the insulation liner and shell, then stitches through all three layers. This is okay on your bed in the house but productive of cold spots outdoors. A variation on the quilt method, used mostly in ultralight bags, is to stitch the insulating batt to the liner at regular intervals while sewing it to the outer shell only around the edges. An ultralight Austrian Gold-Eck bag I’ve used for some time is made this way, and it is far warmer than I expected it to be by the weight alone.
Shingling
2. Shingling laps one insulating batt over the next, like playing cards fanned out. This works on the same principle as slant baffles in down bags to eliminate cold spots. The drawback is that shingles can rip loose along the edges.
Layering
3. Layering follows the same principle as piling up blankets and quilts on your bed for a cold winter night. Potential combinations include two continuous batts, sewn at the edges; two quilted layers with the seams offset to prevent cold spots; or various hybrids: a shingled layer combined with a quilted one, or a quilted one with a continuous batt. Layered bags offer great warmth and durability—at a price. One of my favorite synthetic bags, the Cascade Designs Quantum O° (now sadly discontinued), had layers of Polarguard 3D under a seamless top.
Tuck-stitiching
Some makers tuck-stitch the seams: the fabric is tucked inside and stitched on the inside, so the thread is hidden—safe from abrasion, snagging zippers, cracked toenails, frayed clotheslines, and other destroyers. Tuck stitching, a mark of quality, also increases costs. But Sierra Designs reports that a change to tuck stitching reduced sleeping-bag seam repairs at the factory from one per week to about one a year.
I first heard about ground-level side seams from the original owner of Moonstone Mountaineering, who, like a circuit-riding preacher, visited retail stores himself. Early nylon-shelled bags had tops and bottoms the same width, with lengthwise seams halfway up the sides. But, for the same reason the top sheet and blankets on your bed need to be wider than your mattress, the upper insulating layers in a sleeping bag should reach ground level. This is critical in a down bag with side-block baffles, and no less in a synthetic bag with more insulation above than below. But, as Colin observes, the whole scheme depends on keeping the upside up. If you corkscrew all night, so do the rules of thermal engagement.
The materials used in sleeping-bag shells have changed more slowly than the insulation. Nylon taffeta still predominates, in the 1.6-to-1.9-oz.-per-square-yard range. Lightweight forms, with a fine denier thread (30) are indeed soft and sexy, and by virtue of a high thread count (300+ per inch) quite downproof and somewhat windproof as well. Found on deluxe bags, a light 1.4-oz. nylon taffeta called 30 Max (30d, 350 threads per inch) is treated with Teflon to increase water repellency. This is used for both shell and liner, or as the liner for bags with shells of Gore DryLoft or the new microfiber polyesters. Ultralite Ripstop, a 30-denier parachute nylon with 280 threads per inch that weighs a mere 1.1 oz. is showing up in sleeping bags from high-end makers like Western Mountaineering. It’s highly breathable and allows insulation to loft well but might tend to wear out more quickly.
A variety of polyester taffetas with trade names like Softech are available in shells and liners. Kelty’s warm Pepper Series Polarguard bags have all-polyester shells and liners. One advantage of polyester over nylon is that it feels warmer at first touch, easing those first shivery moments in a sleeping bag.
Gore DryLoft is a lamination of a PTFE (poly-tyranno-fluoridated egg whites?—see this page) membrane to a shell fabric. The original three-layer Gore-Tex was somewhat stiff and noisy for sleeping-bag shells, especially when cold. One dissenting reader compared it to “sleeping in a bag of popcorn.” Such complaints prompted the use of increasingly light and supple fabrics for the two-layer DryLoft. For instance, DryLoft 830 is faced with a 30-denier nylon fabric with 280 threads per inch, weighing 1.1 oz. per square yard, and complaints about noise now range from rare to nil. People who camp in drippy spots—the Maritime Provinces, the Pacific Northwest, snow caves—or who use partial shelters like tarps tend to revere DryLoft and equivalents. But it shouldn’t be thought of as a primary shield against the elements. One sticky problem with regular nylon taffeta is that it “wets out,” forming a vapor barrier that traps moisture in the insulating layer and at times freezes hard. Polar expeditions report progressive ice-ups that turned their sleeping bags into hard-shelled coffins weighing 30 lbs. or more. Since I often use a Gore-Tex bivouac bag, I’ve stuck to regular shell fabric for my sleeping bag. This comes from a suspicion (which a call to W. L. Gore & Associates did little to dispel) that it’s not a good idea to have more than a single layer of waterproof/breathable laminate. Now that Gore’s iron-clad patent has expired, a number of similar proprietary fabrics have appeared, This-Tex and That-Tex.
Internal reflective barriers like Texolite, Kodalite, and Orcothane have disappeared from sleeping bags as abruptly as they burst on the scene. Durability seems to have been an issue, along with moisture transport. Kelty’s Pepper Series bags have a silvery polyester inside (though I wonder if this doesn’t slow sun drying), and some vapor-barrier liners (this page), by definition nonbreathable, are reflective.
The newest trend in shells is microfibers. Also used extensively for clothing, the microfiber itself is a very fine nylon or polyester filament, a great many of which are combined to form a single thread. Thus, a 30-denier thread may incorporate 30 to 40 individual filaments. When the cloth is woven, the spaces between threads are so tight that the fabric is downproof, sheds water and wind, yet breathes. At around 1.7 oz. and 350 threads per inch, the microfiber used in sleeping-bag shells is lighter than what shows up in clothing. Pertex Microlight is a 1.3-oz. nylon microfiber (from Perserverance Mills in Padham, England) that spreads moisture over a broad area, to prevent nylon’s usual wetting out. Durable water repellent (DWR) treatments are applied to ducky it up.
A full go-round with fabrics would be incomplete without at least a bow to the question of color. Conventional wisdom is to make winter bags in the hottest colors, red and orange. Following the ROYGBV spectrum, yellow and green are 3-season models, with blue and violet for summer-weights. But color preferences are so stubbornly personal that retail stores tend to lobby makers vigorously for their favorite hues. At one company, Western Mountaineering, they got so tired of this that for a while they hung their booths at trade shows with all-black sleeping bags in protest.
My observations on color are two. Light shades quickly show dirt and body grime (especially unpleasing with liners), and dark ones, particularly black and dark green, help bags to dry out faster in the sun. So whatever opalescent hue the shell may be, I prefer (vigorously, reasonably) a jet-black liner.
COLIN: Hoods that encapsulate your head when drawn tight form an integral part of most modern mummy-bag shells. They are important: the human animal, with two of its major evolutionary features (brain and expressive face) housed in its head, naturally serves that member with a hugely complex blood-supply system. The capillaries often travel near the surface and are therefore subject to rapid cooling (the head, like a computer, requires a more or less constant temperature—which usually means it needs cooling). The old “facts”—that at 40°F it may, if unprotected, lose up to half your heat production, at 5° up to three-quarters—have been challenged; but there can be no doubt that it is the body’s prime heat-loss area. And perhaps too little attention has been paid to this problem in sleeping bags. Certainly, all hoods are not created equal, or even equal enough.
CHIP: The hood on my first down bag, an REI Skier, was a snap-on option. Like most hoods of that time, it was a flat U-shape edged with a drawstring that puckered it into a head shape. Sierra Designs (beginning with their Cloud Series) advanced the art with hoods shaped to surround the head. Warm-season bags may still have flat, U-shaped hoods or lightly contoured ones. But cold-weather bags, like the Kelty Serrano, have deeply contoured hoods with elastic brow bands or a second drawstring. Floating hoods, unconnected to the bag and thus allowing corkscrew sleepers some leeway, have faded out. The reverse-differential cut (this page), with more liner than shell, is often used. If you’re a wire-chinned chap, some nylon hood liners are so scratchy-noisy they actually keep you awake. Polyesters are quieter. Particularly silent (and warm-feeling) was the Microtherm polyester lining the hood of a Slumberjack Ranger I spent a few nights with. A new hood from Sierra Designs, called the NightCap, adjusts from a squarish fist-and-elbow-accommodating breadth to a rounded head shape with two drawcords. This combination does offer scope for eccentric sleeping styles. And it’s also a further step in resolving the mummy problem. In case you hadn’t noticed, most living people sleep not on their backs, faces toward heaven, but rather on their sides, with knees drawn slightly up.
COLIN: The drawstrings that pull the hood around your face and hold it there mostly come equipped with spring-loaded plastic toggles or other secure but quickly adjustable devices. Sometimes there are two such devices, one at each free end of the cord or tape, near the top of the zipper; but many bags now have a single toggle in the center of the hood on the opposite side from the zipper, so that you can adjust the hood with a single device instead of the two and need not loosen the drawstring if you want to open the top of the zipper (to cool off a little or to emerge briefly in the middle of the night to urinate). This arrangement means that the drawstring ends are anchored near the zipper top, one on each side, and when you tighten the hood you place strain on the zipper and may pull it open. The bag should therefore have a snap or Velcro fastener to take the strain and also keep the draft edge closed. (Velcro is easier to open and close than a snap but can, I hear, grab long hair or even beards.) One designer suggests that perhaps you really need two fasteners, each pulling at a slightly different angle.
CHIP: High on my list of unintended consequences is that sleeping-bag drawstrings and zipper pulls (often adorned with stiff, black nylon tabs) have a tendency to dangle inside the hood, poke me in the face, and summon evil dreams: for instance, kissing a porcupine’s arse. I cut these tiny assassins off and replace them with soft, light-colored cloth tape. The second unintended consequence is that the Velcro tabs used to keep zippers from gapping can damage light shell fabrics by hooking into threads and jerking them out of the weave. The only solution for this is to firmly engage all hook-and-loop fasteners before stuffing the bag, and to keep a weather eye when hanging the bag up to air: a loose tab flapping in the wind can wreak minor havoc.
COLIN: Built-in collars that fit across the sleeper’s chest and so reduce draft through the head opening are becoming more popular. They can be down-filled appendages or plain fabric. And while they may possibly reduce somewhat the bag’s flexibility in wide ranges of temperatures they undoubtedly help keep you warmer in real cold. Warmer, certainly, than any makeshift measures (this page).
CHIP: Here, the Mummy’s Curse strikes again—that is, the deeply lobed yokes seen on so many synthetic bags are designed for back sleepers (or the thermocouple-equipped manikins that companies use for tests). Those of us (the majority) who rest as we did in our maternal tummies do better with a simple, tubular draft collar that lets us roll freely from side to side without fussy realignments. Serious winter bags might have draft-collar tubes both top and bottom. But unless you summer on the summit of Denali, most above-freezing bags don’t need draft collars. One of my favorite hinge-season bags, the Sierra Designs Lewis, is a favorite precisely because it lacks one. My body heat tends to be low on retiring and to ramp up as the night proceeds, peaking about 3 a.m. At that point, I ventilate, which in a draft-collared bag means complicated yogic adjustments of the side zipper. And that in turn requires real thinking—sharply incompatible with renewed sleep. The draft-collarless Lewis lets me tug dreamily at the main zip and thrash my hands to open the top—back to sleep. So, despite the fact that at present this ranks with ranting against the probability of resurrection, I’d rather not have a puffy, air-blocking draft collar above 0°—Fahrenheit!*17
Zippers on bags, formerly gap-toothed nylon-eating marvels, are now almost all nylon-coil type. The best coil zippers are self-healing: if the teeth pull apart, you can zip down and back up and lo! you’re in business again (the first few times, anyway). For a diatribe on zippers-in-general see this page.
Where early saber-toothed zippers could chew their way through a considerable stretch of nylon, leaving plentiful exits for down fluff, the coil type merely snags and stops—so don’t force it. But ultralight fabrics can still get nastily gnawed, and thoughtful makers back the zipper with nonsnagging tape or sew a band of thicker fabric on the draft tube. Double sliders are standard, and desirable, letting you vent the foot without opening the entire flank to the elements. Also nice are swiveling pulls, with a U-shaped track on the slider to let one hangy-down serve both inside and out. Every zipper on every sleeping bag I’ve ever owned was made by YKK. But the WaterTight laminated polyurethane zippers showing up on parkas seem like a good match for DryLoft shelled sleeping bags, if they hold up.
Zippers have migrated. The infamous army duck-down mummies had a front-and-center zip that’s rarely seen these days. Early nylon bags tacked the zips along a side seam, halfway up. On bags with ground-level seams, zippers are mostly likewise, seeming always to end up underneath when you need a fast exit. Some designers now fetch the ground-level zips up toward your chin, for access reasons (but these are the worst as far as lip tickling). On at least one new bag (the Slumberjack Pumori), the zipper swoops clear across from right elbow to left shoulder—the sort of thing you either love or hate. Cascade Designs put the zip on their Quantum bags about 6 inches off the deck, where the side curves into the top. I’m a side sleeper, so this arrangement worked wonders for me, putting the zipper pull right at my fingertips though not right in my face and letting me vent freely without chilly gaps.
Current accessorizing includes upgrade hoods and insulated footsacks. On particularly bitter nights I’ve draped my down parka or vest over the foot of my bag, to the same effect. The new Sierra Designs bag I’m testing has four discreet loops sewn into the ground-level seams that mate up with the Pad Lock—four plastic clips and a lock on a length of light shock cord—to keep your pad where it belongs. Another clever extra is Mountain Hardwear’s zip-in expander, which adds 8 inches of girth—a boon to the pregnant (down or Polarguard, 12 oz., $50). Some bags have sprouted little Velcro-flapped goodie pockets. Mountain Hardwear’s Tallac bag includes a headnet that stuffs into a chest pocket, for rapid deployment. The only two items I’ve put in a sleeping-bag pocket are a flashlight and a handkerchief. Eyeglasses seem risky. Zip-together lovers might stash breath mints, tissues, and condoms. For the devout, the pocket could hold a compact Bible, Koran, etc. For the apprehensive, pepper spray.
Unless you hang your bag for storage, a necessary adjunct is a storage sack that protects without ruinously overcompressing the insulation, as a stuff sack does. These come with most high-quality bags, in cotton or mesh, or are easily found in shops. A king-size cotton pillowcase from a thrift store also serves.
Vapor-barrier linings (VBLs)
COLIN: VBLs have been around for years. But although embraced fanatically by a few they have not caught on. Some people, including me, still like them; others, including Chip, like hell do not.
For a brief summary of the theory behind VBLs, and some discussion of the practice, see this page. I have good reasons for attacking the matter there, in the Clothes Closet, rather than here; but understanding the theory so that you can practice properly is a major component of VBL usage, so I’m afraid you’ll have to read most of this page and this page if you’re to grasp the meat of what follows.
Both theory and practice are simpler with sleeping bags than with clothes, because in a bag you lie more or less still and your metabolic rate changes only very slowly (though the practice is complicated by your being mostly unaware of temperature changes, and the need to adjust, until cold or heat wakes you up). But even with VBL sleeping bags you must understand what you’re playing with—which is something very different from a conventional breathing-shell bag.
More than three decades ago I tried a VBL bag by Warmlite, a pioneer in the field, on a five-day test up to 12,000 feet and down to a windless 16°F. In a tent, wearing little or no clothing, I found I was far too hot, soon began to sweat, and simply could not adjust the rather complicated bag to an all-around comfort level. Now, the real trouble may have been the bag’s built-in foam pad. I normally lie first on one side, then on the other, moving the whole bag with me and thereby keeping any opened zipper to my front; but the built-in pad could not move with me and the opened zipper was, in one of my lying positions, bound to run close and cold to my curved back. (A reader later wrote that he’d had a similar unsatisfactory experience, and also thought the trouble was the built-in pad.) I had further minor difficulties too (though the makers assured me with heat that I had misused the bag). In the years since, I’ve met many people who have tried VBL bags and found them wanting. The reasons could lie in extraneous matters like that built-in pad or such personal idiosyncrasies as high metabolic rates. But I suspect that in many cases the bags were simply used in temperatures too high for the system. The maker of excellent VBLs once told me that he felt they were really not for use above 35°F. The difficulty is, of course, that many nights may begin much warmer than that but end up much colder. And one night may be much warmer, the next much colder, especially in the mountains. Bags with built-in VBLs are simply not versatile enough for such very common conditions.
The way to achieve versatility is fortunately simple: a removable VBL. I have for years carried one on all but the most guaranteed-warm trips. I’m convinced that it extends the low end of any bag’s comfort level by at least 10° and probably by 20°.
The price in weight and bulk is small; in money, very reasonable. I use a simple, coated ripstop half-sac (no longer available) by Moonstone of California that weighs 4.7 oz., takes up about as much room as a pair of jockey shorts, and cost $18. True, I normally also carry a matching VB shirt (6 oz., $35—see this page) and use it with the half-sac, but the shirt performs major daytime functions—and other warm torso clothing would often be enough in conjunction with the half-sac. By taking a bag that’s a tad on the light side for a given trip (or even several tads) and regarding the VBL as a reserve for cold occasions I can save considerable weight and bulk. And if temperatures drop markedly during the night I simply slip into the VBL, which I have put ready, inside the bag. My Moonstone half-sac extends up to my upper chest and is held there by an elastic “waistband.” Provided I wear polypropylene underwear (this page) I experience little or no damp or clammy feeling—and none of the uncomfortable wrapping around legs and torso that some people report with full-length liners. I find the half-sac particularly useful with a very light bag (this page).
Some sleeping bags have a snap or two to anchor an optional liner, and the makers tuck a VBL liner into the margins of their catalogs. Stephenson’s makes VBL items from a somewhat-stretchy urethane-coated 2.2-oz. nylon knit called Fuzzy Stuff, with the soft side skinward. Feathered Friends sells a VBL liner in four sizes (about 6 oz., $35–$37). For “extreme winter camping” Western Mountaineering sells the Hot Sac, 1.1-OZ. polyester with a shiny reflective lining (7 oz., $65), that can serve as an emergency bivouac bag. For a makeshift version, get an aluminized polyester “emergency bag” for $10 to $12, and try it with wicking long underwear and socks. (If the VBL aspect doesn’t thrill you, you can always use it as a groundsheet.)*18
But with removable liners we’re beginning to move over from traditional, more-or-less-one-purpose sleeping bags into
The idea is hardly new. One early approach was Warmlite’s “solotriple” bag that I described in The New Complete Walker (with two zipper-off topsides of different thicknesses that can be used alternatively or together, giving a solo sleeper three bags in one). Camp 7 for some years offered a lightweight synthetic-fill bag that could be used alone as a summer bag but would fit as an outer shell around any of Camp 7’s main line of down bags—boosting their warmth and also protecting the down from external moisture. A removable VBL greatly increased the cellar range of either bag or of both together.
CHIP: The zipper on my ultralight down bag is on the same side as the one on my 15°F model, so despite their being from different makers I now double them up—8 inches of loft—for really cold nights. But makers of real system bags offer a calculated fit, matching zippers, etc. Mountain Hardwear has a choice of a 40° down (2 lbs. 8 oz., $165) or 45° Polarguard HV mummy bags (2 lbs. 2 oz., $105), or a 50° Polarguard HV barrel-shaped bag (2 lbs. 10 oz., $115), to fit inside their 3-season models. The upgrade hood (6 oz.) seems like a necessary component. Feathered Friends, among others, make certain bags with systemic features: their Great Auk (2 lbs. 1 oz., $288) is a roomy 20° bag with a hood and a built-in pad pocket, designed to engulf a summer or 3-season model, with a 40° boost in its comfort rating. A slick 4-season combo is the Great Auk and a Feathered Friends Rock Wren (1 lb. 15 oz., $225), a unique summer bag with zippered armholes and a drawstring foot, that doubles as a full-body camp robe. With the Rock Wren, you can get up and make coffee without leaving your sleeping bag: scary. You can also augment the Rock Wren with a down parka and booties, for hard-core bivy sacking.
Any of four Wiggy’s sleeping bags, filled with a proprietary resin-bonded fiber called Lamilite, will fit into a hooded overbag that, alone, works to 35°F and adds roughly 40° to the rating of the inner bag. The Wiggy’s Ultralite (3 lbs. 8 oz., $146) is rated at 20° alone or to –20° with the overbag (2 lbs. 8 oz., $144).
The inflatable Cocoon 4, by Pneugear, is probably the most elaborate sleep system going (a brochure showed up in my mailbox, but my offer to test-and-return elicited no reply). It has a contoured, 4-inch air mattress mated to an inflatable down-filled top: air pressure regulates the loft. The ensemble includes Primaloft-filled hood, zip-on stormfly and bug netting, titanium stakes, repair kit, and of course, a built-in pump (10–11 lbs., $1395).
At the spare end of the spectrum is the Fur sleep system by GoLite. Rated to 20°F, it’s based on a Ray Jardine design that eliminates not only the hood (keep your hat on, says Ray) but also the underside of the sleeping bag: a 2-inch Polarguard top quilt Velcros around the edges to a tapered ⅜-inch polyethlene foam pad (6 oz.). Including the pad, the small size weighs 2 lbs. 2 oz., the medium 2 lbs. 8 oz., and the large 2 lbs. 14 oz. ($198 each). Jardine’s original sleeper was a double, boosting the warmth and shaving the weight, and GoLite plans to build one, along with colder-weather models.
For the single/double option, look for a barrel-shaped bag (with a foot that unzips and perhaps a detachable hood) that mates with a coupler, or doubler. This is a single layer of fabric with straps or pockets for pads and a pillow sleeve up top. The bag zips to the undersheet for a warm-weather paso doble. I cherish an old Moonstone Upside-Downside because it not only incorporates this solo/duo possibility, but the bag itself has thick and thin sides. This not only lets you (solo) flop it for warm or cold nights but also gives couples a warm side and cool side. The advantages of this system, for mutual comfort and conflict avoidance, are brilliantly clear—plus it saves weight and bulk and cash. It also makes sense for those avid walkers with a partner who camps only once in a while. To go with their Flying Wide down bags, Feathered Friends makes couplers: the Toucan Ultralite in 1.1-OZ. ripstop nylon (9 oz., $52), and the Toucan Deluxe in a poly/nylon blend (1 lb. 1 oz., $63). Mountain Hardwear’s Duet is 12 oz. and $65.
COLIN: Any good sleeping bag is now a damnably expensive item. But the range is large—from $125 for a reasonably serviceable 2- or 3-season synthetic-filled semi-mummy to over $700 for sophisticated, superbly crafted, custom-made models for the coldest weather. Mostly—surprise!—you get what you pay for, and you must make your own decisions about what you can afford. I’m aware that backpackers who use their equipment only once or twice a year may not feel justified, in view of other responsibilities, in spending the sums now demanded for really good bags (though see this page). The current prices may curdle your financial blood, but remember that when you take a sleeping bag out of your pack as night falls on a frigid, windswept mountain you understand without having to think about it that dollars are meaningless frivolities.
The usual criterion for gauging the efficiency of a sleeping bag is the lowest temperature at which it can be used with comfort. “This bag is excellent for use down to 25°F,” the catalog may proclaim. Such generalizations have their uses. Beginners need guidelines. But there’s a serious danger that people may accept the figures uncritically. Many factors other than temperature are important, and a wide variation in one or more of them can throw out the whole works. Still, the general rule is sometimes promulgated: “For summer use, with temperatures above freezing, 2 pounds of high-quality down; for temperatures down to 0°F, 3 pounds.” (For most synthetics, increase weights about 35–40 percent.) For more on fills, see this page. For construction and other shell desiderata, see this page. You can check the construction of most blow-filled bags light enough for backpacking by simply holding the shell up to a strong light.
One way sometimes recommended for checking the probable efficiency of both fill and construction is to measure what’s called free loft. Unroll the bag on a flat surface and shake its edges with a gentle fluffing action that allows air to become entrapped in the fill. Then measure the height of the bag at its midsection. The amount of loft depends on both the quality of the fill and the efficiency of the shell construction (see differential cut, this page). Different makers apparently measure loft in different ways, but it seems reasonable to assume that, as is claimed, a relationship exists between free loft and heat-retaining efficiency. What the exact relationship is I have no idea.
Free loft
It’s important to remember that temperature-tolerance figures for sleeping bags are now generally based on the assumption that you sleep in a tent with good insulation under you. A bag that keeps you comfortably warm at 32 °F on a full-length foam pad will obviously not begin to do so if you roll it out on bare ground. And the same kind of difference exists between different roofs—tent, sky, or intermediate. The temperature inside a tent may run 10° or 20° higher than outside (see table, this page). Again, much depends on what clothes, if any, you choose to sleep in. My solution to all this is always to carry a pad (or, occasionally, an air mattress) and to take a sleeping bag, perhaps with a separate VB liner, that I judge will keep me warm under normal conditions for the time and place if I sleep without clothes or roof (except in snow), and will just about do so under the worst recorded conditions if I wear every garment in my pack and protect the bag with every form of shelter I’m carrying—whether a simple poncho or a Visklamp-and-polyethylene roof or a tent. Nowadays I seem to guess about right. I can’t remember a night in the past 40 years when I’ve slept in a sleeping bag and been uncomfortably cold. Now, it may be that I’m a little overcautious. “When it comes to sleeping bags,” a store owner once told me, “most people overbuy—and then sweat their arses off.” But in a modern, full-length-zipper bag it’s easy enough to stay cool. For an example of how “overcaution,” at least in support items, can pay off when it really matters, see this page.
One major difficulty with temperature ratings for sleeping bags is that the relationship between air temperature and what the human body feels is a remarkably tenuous one.
First, weather is much more than just temperature. Above all there’s wind. A bag that keeps you snugly warm in the open on a calm 10°F night may be frigidly inadequate at 32° in a 30-mile-an-hour wind. See, importantly, the windchill table on this page—though laminated and microfiber shells may be taking the edge off the wind problem. Humidity comes into it too. Dry air is a poor conductor of heat, damp air a good one. So in wet weather the air pockets held in the fill of your sleeping bag insulate less efficiently than in dry. This is no idle theorizing. Using equipment that has proved entirely adequate in dry weather at freezing and below, you may find yourself decidedly cool in a temperature of 40° after heavy rain has saturated the atmosphere, even though your bag remains dry. It’s even possible for a drop in temperature to make you feel warmer. At 34°, with the air full of water vapor, the weather may seem rawly cold. When the temperature falls a few degrees and the moisture that has been ruining the insulation freezes, you’ll probably feel much cozier.
But the most variable factor of all is the individual.
Some people “sleep cold,” others “hot.” The theory—no more—is that the bigger you are and the more generally active, the warmer you tend to sleep. After camping under various conditions with other people using similar equipment you’ll probably get a fair idea of your own rating. Or you can tap indoor experience: do bedmates regard you as iceberg or hot-water bottle? (This is a purely thermal rating, of course—nothing to do with the factor involved in that libelous dig, “Which would you rather have—an English lover or a hot-water bottle?”)
Remember, too, that no individual is a neat, predictable, laboratory-conditioned guinea pig. At different times he may react very differently to similar conditions. Tiredness, emotional state, and fullness of stomach certainly come into it: someone who sleeps snugly in a given bag at zero when he’s rested, secure, and well fed is unlikely to do so if he’s exhausted, worried stiff about a sick companion, and hasn’t eaten since morning. (Don’t overlook the eating business. After a good meal your high blood sugar—available for heat production—will mean you sleep much warmer than on an empty or half-empty stomach. So if you tend to dine early consider eating a sugar-rich snack just before you go to sleep—even if you follow the Zone Diet.) Again, personal variations may be simply a matter of not being used to the cold or the heat or the elevation or whatever prime stress the situation imposes. Our bodies need time to adapt to radically changed conditions. Two or three days’ acclimation may be plenty; but if the change is too abrupt those two or three days can be distressing.
The solution is to get used to a new environment gradually. One word for this process is “training.” In Europe during World War II we often used to sleep in the open or in slit trenches in subfreezing weather with nothing over our distinctly temperate-country clothing except a thin antigas cape. I don’t say we liked it. And I don’t say we slept very well. But we slept. We were young, we were fit—and we got used to it (mainly, perhaps, because we had to). By the time I made the California walk I was a dozen years less young; but after a month of walking I was probably just as fit. Yet I remember a night in Death Valley, when I had no sleeping bag, that might make you wonder if I were the same person. That warm desert night I put on all the clothing I had—which was certainly as warm as, if not warmer than, British battle dress. Then I wrapped my poncho around me and curled up in a little gully. I had just finished a 20-mile day, and I promptly fell asleep. But before long I came half awake and tried to pull the poncho more closely around me. There was no wind; nothing that could even be called a breeze. But cool night air was moving slowly and steadily across the desert’s surface. Like the tide advancing across mudflats, it penetrated every corner. It passed over me. It passed around me. It passed underneath me. Soon it seemed to be passing through me as well. Minute by minute it sucked my warmth away. No matter how closely I cuddled to the gully wall, the cold bit deeper and deeper. For shapeless hours I fought the sleep battle. Occasionally I dozed. More often I lay three-quarters awake, telling myself I was half asleep. By two o’clock the dozes had become unreal memories. And at 3:30 I got up, packed my bag and headed north into the darkness.*19
Later I learned that the temperature that night never fell below 58°F. This is admittedly an official reading, taken 5 feet off the ground; but a thermometer lying beside my bed just before I left would probably have registered somewhere around the same. Now, 58° is a very mild temperature. But the reason I felt so bitterly cold is simple: I wasn’t used to it. I’d been walking through deserts for more than a month, in day temperatures that had risen to a peak of 105°. Recent nights had been warm too, and the day I entered Death Valley the minimum temperature had been 80°. But what mattered most was that all this time I’d been sleeping in a highly efficient 2½-lbs.-of-goose-down mummy bag. Then, two days earlier—wanting to cut my load, and feeling I didn’t need a bag in night temperatures that seemed likely to fall no lower than 80°—I’d given it to two Death Valley rangers who checked my arrival at a spring at the south end of the valley. I arranged to collect the bag when I passed through a ranger station a couple of weeks later. But that same night an unexpected storm sent temperatures plunging. The next night I found myself curling up in that miserable little gully with no protection except my clothes and poncho—and, what was even more important, with my body unprepared for the shock of sleeping in what seemed reasonably warm conditions. (Note, though [this page and this page], that two-thirds of maximum windchill effect occurs when the wind is blowing at only 2 miles an hour.)
Acclimation can also work the other way. One September I spent a week walking along a mountain crest that rarely fell below 12,000 feet and rose at one point to 14,000. In clear autumnal weather the panoramas and the wind were both breathtaking. On the third night my route took me down off the crest for the only time all week, and I camped in a sidecanyon at 10,000 feet. At dusk my bedside thermometer read a bare degree or two below freezing. Because I was trying out a very efficient experimental mummy bag that had been designed for Alaskan mountaineering (it had 3 lbs. of down and no side zipper), I didn’t bother about shelter, except to camp just below some bushes. The bushes, I felt sure, would blunt the almost inevitable down-canyon wind. To my surprise, no wind blew. Soon I was far too hot to sleep. I slipped into my wool shirt and a very thick, hooded down parka, then eased up partway out of the sleeping bag, and pulled on longjohns and pants. With the sleeping bag pulled loosely up around my midriff and a pair of big leather gauntlets to protect my hands, I immediately fell asleep.
I woke at dawn, glowingly warm, to find the thermometer registering 22°F. But what really surprised me was that during the night one glove had come off and my bare hand, lying unprotected on the grass, felt perfectly warm. The circulation in my hands had always been rather poor in cold weather, and I wouldn’t have believed it possible for one of them to feel pleasantly warm at 22°—even with the rest of my body glowing and the air very dry. The point is, I think, that I’d been up in cold, windy country for two days. I very much doubt if the hand would have felt so warm under identical conditions on the night I left the car.
I hope this long discussion has not led you to believe that temperature ratings have no value as a means of expressing a sleeping bag’s efficiency. I repeat: they’re useful guidelines. But if uncritically accepted as absolute statements they can be dangerously misleading. Bear that danger steadily in mind when you’re making your choice. And ponder ponderously. Buying a sleeping bag is a serious business. If you make a mistake you’ll have many long, slow, purgatorial hours in which to repent.
These days the mountain shops tempt us with serried ranks of gorgeous, gossamer, butterfly-colored sleeping bags—gleaming, curvaceous works of art that almost demand to be stroked. Faced with such an array and the need to choose one among all those superb creations, it’s often difficult to know where to begin.
In easing toward a decision you’ll probably—after weighing the general and sometimes subjective elements I’ve outlined—move on to a relatively objective survey of shell materials, including laminates, microfibers, and VBLs. (You will, of course, buy only a bag that fits you: one so short that your feet press against its end will prove a very expensive mistake.) But in the end the elimination process may boil down, economics aside, to deciding which minor variants seem to offer some advantage. If you like a bag to turn with you as you roll over (which I do, so that a partially opened zipper stays in position along my front, where my natural curl will hold it at a distance, rather than close and cold along my back), then a slender, form-fitting mummy will probably suit you best. But if you prefer—or rather think you prefer—being able to turn over in a more or less stationary bag, then consider ampler envelopes—the barrel-some daddies or even unabashed biggies—or at least avoid those contoured to fit your feet. Next, cast a critical eye on all hoods. Then examine in the beam of your druthers such accessories as drawstrings and built-in collars. And look closely at zippers and the draft flaps or block baffles inside them. See if the base of the flap is sewn right through and might create cold spots. Check that the flap (or baffle) lies snug along the zipper line. If in any doubt on this score (and maybe even if not) take the bag into a strong light, put your head inside, and see whether, with the bag in the kind of position it will assume when full of you, any gaps show. If they do, take the bag back to a dark corner and leave it there.
In the end, though, your decision may rest on your assessment of workmanship.
Meticulous workmanship is the key to toughness and long life in any first-rate backpacking bag, stripped as it must be of every unnecessary gram. It is no assembly-line product. To ensure high quality, at least one maker has each bag “constructed by a single seamstress who is personally responsible for that bag.” In the finished bag almost the only outward and visible sign of this inward and invisible pride and expertise is the stitching. Check it carefully. Check it most of all in difficult places, and those that will undergo most strain—such as around the top of the zipper. But I suspect that most backpackers are as poorly qualified to judge the quality of workmanship as I am. (Note that, in spite of earnest consultation with manufacturers, I have not—except for the words on tuck stitching [this page]—found it possible to describe just how you should rate stitching.) In the end the safest way is probably to check reputation. Don’t just shop around; check around. Pay some attention to good reports, great attention to bad ones. Finally, you may even want, if you can, to try out the model you favor by borrowing or renting one.
The comforting thing about the present plethora of gorgeous sleeping bags is that it has become difficult to go diabolically wrong. Fierce competition and the high costs of both materials and labor—which virtually force anyone entering the market to aim for a quality product—mean that there are few if any crummy bags around. You won’t find them in reputable mountain shops or specialist catalogs—and probably not even in general sports stores.
For years now I’ve used only two bags for backpacking. The makers of both are out of business, but the bags’ general specifications may be guidance-useful. The first, lighter one is a Bear Cub by Blue Puma (regular size, 15 oz. of 600-fill-power down, 3- to 3½-inch loft, rated to 35°F, weighs only 1 lb. 12 oz.—which is what entranced me when I bought it, almost 20 years ago). The weight is achieved by stark simplification. The bag even dispenses with baffles: it’s sewn through, like a light down jacket—the way I said no self-respecting modern bag was sewn. But it works. Like hell it works. It has long been my standard mild-weather bag—often backed by a Moonstone half-sac VBL (this page). It proved itself early by coddling me through a windless 18° night, in a tent. And down the years it has kept me warm and happy at many damp, windy, around-freezing camps.
My second bag is a mummy custom-made by Down Home—which replaced my Trailwise Slimline when that trusted old friend beat me to the punch and suffered decrepitude beyond usefulness. The transverse-baffled Down Home weighs 2 lbs. 12 oz. Its temperature rating, now befogged by time, is probably 10°F; its down fill power 700 or 800. Loft: still 8 inches. To hold the side-opening baffle closed, an internal zipper backs the two-way, almost-length-of-the-bag main one. No collar. Simple hood with toggled drawstring and opposite-side snap fastener plus Velcro strip. The bag has done me proud under all kinds of conditions; and the little Bear Cub bag fits inside it—imperfectly but usefully—to form a cold-weather rig. But I’ve used the combo in the field no more than two or three times: in truly bitter weather I’m now old and wise enough (or do I mean chicken enough?) to stay home.
CHIP: As choices go, deciding what to sleep in seems to rank right up there with deciding who to sleep with—so my sleeping-bag tests for this book have been selective. Rather than reeling off a list of bags I haven’t slept in, for the most part I’ll describe my often-lofted sweethearts. Bear in mind that our concern here is mainly backpacking, and no less, backpacking for fun—rather than expeditionary climbing, polar traverses, etc.
Below zero. Until recently my deep-winter bag was a late-Pleistocene Holubar (circa 1976), cinnamon and tan, with 3 lbs. of down, V-baffles, and a bit of age-related clumping in the hood. For that hard solstice chill (ah, distinctly I remember) I’d insert a down ultralight inside. I did nearly piss myself a few times, too sleep-muddled to solve the zipperistic puzzle I’d set up. But mostly, the bag and I got along.
A few years back, a would-be hero showed up at my house after driving hundreds of miles, having somehow forgotten his winter bag. So, with a certain amount of chin scratching (signifying severe inner stress), I loaned him mine. What afflicted me wasn’t so much plain distrust as the idea that anyone hapless enough to roar off on a winter mountaineering trip without a sleeping bag probably wouldn’t return. So I pulled out a stack of catalogs and picked out a new one, just in case: a Western Mountaineering Puma (0°F, 2 lbs. of down, 8 inches of loft, 3 lbs. 1 oz. total, $400). My old bag did come back—and I had my next one picked out.
But instead of taking the financial plunge, the last two winters I’ve taken the combo approach. Most people would consider the Sierra Designs Lewis (now replaced by the stretch-seam Night Fall long at 3 lbs. 2 oz., $240) as a 3-season bag. I think of it as my winter ultralight: a 15°F down bag that’s blessedly free of a draft collar or other fashionable impediments. For bitter midnights, I line it with a Western Mountaineering Iroquois (long, 1 lb. 9 oz., $205; see next page) that closely resembles Colin’s Blue Puma. And I like layering up—except for the damn zippers.
Hinge season. For me this means fall days when the jet stream dips southward and rain changes to snow. It also means the high northern spring, with long, sunstruck days and subfreezing nights, and a snowpack that alternates between boilerplate and slush. That is, it means being alert to change, and rolling with it—as much as I love downy old down, I find synthetics a blessing for hinge-y conditions.
Recently I adopted a Sierra Designs Hibernator, filled with 3 lbs. 4 oz. of Polarguard 3D and rated to 0°F (4 lbs. 15 oz., $259). What intrigued me is the Lycra baffling (known as the Flex system), the intent being to reduce the empty and potentially cold volume of air inside while allowing freedom of movement: good for those dragon battles and demon loves. The puckered seams didn’t thrill me at first, but after quite a few nights the Hibernator’s practical roominess (6 full inches of stretch) does. I can roll from side to side without corkscrewing the bag and can draw up my knees without pressing the liner out into a cold spot. The broad-browed hood—called a NightCap (see this page)—is another departure. The ground-level main zipper swerves up to the chin (I hacked the factory-installed lip-tickling zipper pulls off the first night). A second short zipper opposite the main one lets you vent or shut off the alarm watch. Four discreet loops on the ground-level seams anchor a Pad Lock—a length of light shock cord with four plastic clips to corral wandering pads. One drawback: like many warm synthetic bags, it’s somewhat bulky when stuffed.
Three-season bags. This rather broad class takes in bags rated from 15°F to perhaps 40°, depending on where your three seasons are spent. I think of a 3-season bag as being mostly for cool summer nights on high. When you wake up, there’s a faint mist on the lake and the grass gleams with dew. But if it freezes, you can pull on a cap and longjohns, and wake up toasty. Or on the other hand, if it’s balmy, you can open things up, reaching a balance somewhere between full frontal nudity and the Heat Death of the Universe.
A 3-seasonish bag I’ve had for years is the Moonstone Upside-Downside, a long-discontinued semi-rectangular Polarguard bag with a doubler, already described on this page. A couple of years ago I tested a newer Moonstone, a Minima Long of Polarguard 3D rated for a low of 25 to 40°F (2 lbs. 11 oz., $165). The liner was made of something called T-Silk, with “ZAP Electrostatic Action to move excess moisture away from the user.” On one sad occasion, I had to tromp a couple of quarts of water out of the Minima and then spend a brisk spring night in it. I put on wicking underwear and socks, and crept in—a mite chilly at first. But I actually got to sleep and woke up the next morning warm, having dried out the bag (except for a patch under my butt) with body heat.
Ultralights. Being not just a warm but a geothermal sleeper, I use ultralight bags in lieu of the usual 3-season choices. My ultralight baptism was an Austrian Gold-Eck Schlafsäcke (i.e., sleeping bag) weighing 1 lb. 8 oz. that stuffed into a Quaker Oats box. God, was I smitten. Until I schlafsäcked out one 3° night (for the horror, the horror, see this page). Summed up, it was less than Eck-static. But the gossamer sirens crooned on. So I ordered a Western Mountaineering Iroquois. The shell is a subtle blue, the liner black. The foot section has a cut like the bust on Marie Antoinette’s favorite ballgown. Yet despite the legendary quality of Western Mountaineering’s down and construction, I was suspicious of the sewn-through box quilting. But the anticipated cold spots didn’t show up. Instead, the temperature range is magnificent—and it’s now my 3-season bag. Summed up, the Iroquois (long, 1 lb. 9 oz., $205) makes me feel that money itself means very little, compared to a good sleeping bag.
COLIN: These bags are usually made of cheaper materials than full-size ones, are more simply constructed, and are filled with synthetics rather than down, no doubt on the reasonable assumption that if you invest in a high-quality bag you’re not going to buy something your children will grow out of within a year or two. But price isn’t the only reason synthetic fills are more popular than down: synthetics can be repeatedly rinsed and washed; with down you can, particularly during the diaper years, land in big trouble.
Lower-quality children’s bags apparently sell very well. One possible reason is that children tend to sleep warmer than adults. In theory they should sleep colder: their smaller bodies, with a wider surface-to-volume ratio, should lose heat faster. But to balance this factor their metabolism tends to operate at a higher rate. What happens in practice is a matter of opinion, but a limited poll I conducted among friends tended to support the opinion of one mother of five children ranging from 4 to 13 years old, whose family seemed to spend half its young life camping or cabining in the mountains. “Yes,” said this seasoned troop leader, “I’d say there may well be something to the sleeping-warmer business—certainly when the kids are young and covered in puppy fat. I’ve found our 4-year-old almost out of his bag on quite cold nights, still fast asleep. Once children start beanstalking up into their teens, though, it’s rather different. It could easily be that at that stringy stage they tend to sleep somewhat colder than adults.”
CHIP: In 1998, when the Backpacker Annual Gear Guide included a listing of children’s outdoor equipment, the purveyors of kids’ sleeping bags were: Eastern Mountain Sports, Feathered Friends, Ferrino, Integral Designs, Kelty, L. L. Bean, Lafuma, Molehill Mountain Equipment, Peak 1, REI, Slumberjack, Stephenson-Warmlite, Tough Traveler, and Wenzel. The bags ranged from the low-budget baby-fat types to relatively sophisticated youth models with shaped hoods, draft collars, etc. Lowest price was $21 for a Wenzel Jr. Espirit (2 lbs.). Highest was $480 for the Stephenson-Warmlite Triple (3 lbs., including pad). Median cost for synthetic bags was about $60. High-quality down bags for children were the Feathered Friends Fledgling 68-incher (1 lb. 9 oz., $195) and Fledging 72-incher (1 lb. 12 oz., $210).
For a child, a good ¾-size self-inflating pad does nicely, as do the ¾ Cascade Designs Ridge Rest (9 oz., $15) and ¾ Z-Rest (11 oz., $24). For adolescents, the Artiach midlength pads, at 63 inches (see this page), are a good fit. Or, for that matter, an Ensolite pad can be trimmed. But don’t expect your kids to nestle down happily on your old, cracked Ensolite pad while you yourself are Therm-a-Resting.
COLIN: Some people don’t mind sleeping without a pillow; others even prefer it that way. Unless I’m too tired to notice I find it disconcerting not to have one. Minor back trouble sometimes forces me to carry a specially shaped foam pillow (my “security pillow”), but mostly I still make do with older, more orthodox devices. For me, an air mattress with pillow (this page) is ideal. With a self-inflating or foam pad I normally just roll up my long pants or down jacket or another garment and stuff it (or them) under my head. If you push the garment partway into a stuff sack you can fine-adjust pillow size to meet your need of the moment. Sometimes I bolster the clothing with a plastic canteen or the day’s-ration food bag. If the night is cold enough to make me wear all the clothes I’ve brought, I may use a canteen alone. This arrangement helps keep the canteen unfrozen; and because I’m sure to be wearing my balaclava helmet and perhaps a hooded parka as well, it’s tolerably comfortable. Or I may pad the canteen with the packbag or ration bag—making sure that soft food such as cereal is directly under my head. A convertible stuff sack from Liberty Mountain Adventure (8-by-18-inch, $12; 9-by-20-inch, $14) holds your sleeping bag and then reverses to serve as a clothing-filled pillow with a fleece panel. You can, of course, buy a separate, inflatable pillow; a synthetic-filled one; or, much more cheaply, an ordinary zip-top bag.
On sand or other loose soil the simplest and most comfortable pillow is a roughly banked-up guillotine block. No matter how much you want a soft pillow, there are precious few places left in which it is justifiable to use bough tips or moss or any natural material. Occasionally, manna falls. One reader reports that when, as a member of a large party, he was the bearer of an inflatable plastic arm splint, he found it made “a luxurious pillow.”
If you have any kind of back trouble (not exactly rare in homo backpackerens) you may find that when sitting up in your bag or lying on your back you need some kind of knee support. Anything from a down or pile jacket through food bags to the half-empty pack can be pressed into service, either inside or outside the bag. This knee pillow must be so arranged that when you turn over onto one side your knees can circumnavigate it with next to no assist from your conscious mind.