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BASIC TECHNIQUES

Some people are interested in making leather fashion accessories, in which case they are most likely to want to learn pattern-cutting and constructional techniques for making handbags and garments. The wide range of commercially available (sometimes brightly coloured) chrome-tanned leathers will be of interest to them, and some may consider buying a heavy-duty sewing machine at some stage (second-hand machines can be good value). Fashion accessory enthusiasts will wish to learn about leather as a way of augmenting their present dressmaking or fabric-related skills.

Others prefer the more intricate craft-type leatherworking, normally involving the use of vegetable-tanned leathers, which are hand stitched or thonged and carved and/or dyed. Strikingly individual items can be made in this way, and the scope for anyone with flair and artistic ability is limitless, since any design can be transferred to a leather panel or belt. Designs can also be copied from books and pictures and transferred in the same way.

Between these two extremes lie a variety of items that fall into neither or both camps. Below is a guide to the main methods of construction used within the leatherwork industry.

Fig 17 Cut-edge construction.

Fig 18 Turned-over-edge construction.

Cut-edge work The leather is joined, flesh-side to flesh-side, and the cut edges stained to match the main surface areas. Good-quality leather, such as pig or calf, is required. Wallets and purses can be made in this way.

Turned-over-edge work The outer leather edge is cut with an overlap that is turned over the inner layer (s), before stitching begins, so that no cut edges can be seen: the rounded grain side of the outer layer covers them up. Before turning, the leather along the folding part of the outer layer needs to be skived (pared), that is thinned down from the flesh-side before the turnover is made so as to avoid making a bulky seam. Goods like wallets, purses and jewellery rolls can be made in this way, using high-quality leather. This is a better, more professional, type of construction. Leathers such as pig or calf are often used for turned-over-edge work.

Semi-limp The leather is partially stiffened with paper for items such as diaries and books. Rexine is often used for making this kind of product.

Stiffened Leather is applied over a foundation of board or wood. This is necessary for memo-pads, desk-blotters and photo frames. Cheaper thin leather, such as skiver, can be used for this, as well as rexine.

Boxwork Same as stiffened, but the leather covers a box constructed from plywood or MDF. Jewellery boxes, card boxes and document cases can be made in this way.

Moulded Three or four paper layers are bonded together using PVA adhesive around a mould. Examples of moulded work are instrument cases and cigar cases. Leather itself can be moulded too.

Zipped Zips are attached to such items as writing cases and manicure cases.

Classification of leather goods

Light leather goods Wallets, purses, soft  leather handbags, jewellery rolls.

Heavy leather goods Heavy belts and  more robust handbags: items that may be  carved and stained.

Built-up work Photo frames, jewellery  boxes, attaché cases.

Germane to these seven methods of construction are various essential techniques, the first of which is cutting.

CUTTING

THE CLICKER KNIFE

The best way to use a clicker knife is to hold it as you would a pencil and draw it towards the body, always cutting against a hard surface like a steel rule or thick cardboard (or wooden) pattern. Either straight or curved cuts can be successfully made in this way, and, since the knife is small, it is accurate and the user always has complete control. Those who are right-handed should keep the left hand to the left of the cutting edge, holding down the pattern or metal rule; vice versa for left-handed people. The clicker knife is ideal for cutting paper, card, and thin and thick leathers. It blunts particularly quickly when cutting card or paper, so remember to sharpen it regularly even when not actually cutting leather itself.

Fig 19 Using the clicker knife.

Cutting Heavy Leather

When using the clicker knife on heavy leather, there are a few points to be borne in mind:

• Cutting heavy leather often requires several strokes of the clicker knife before the full thickness of the leather is pierced.
• Regular sharpening of the knife is required, as it soon blunts.
• Take care to support the knife blade securely against the card pattern or a metal ruler or straight edge.
• When cutting curves, begin with a gentle incision and repeat the process many times, cutting progressively deeper. Once a deep groove is established, the knife will follow this established route automatically.
• Position patterns on the skin carefully, bearing in mind which parts are most visible (for example, the front flap and the front pocket of a handbag), and avoid using stained or damaged leather for these. Small flaws or discolorations of the surface finish may be permissible for the gussets of handbags, or even the back of the main body.

Safety when cutting

• Press downwards, not sideways, as cutting commences.
• Cut against a thick metal rule or cutting pattern to prevent the possibility  of the knife sliding sideways onto the  non-cutting hand.
• Keep the blade sharp: blunt blades  require more pressure and consequently involve more risk.
• Never rush: the heavier pressure  required to effect a cut in thick leather  exacerbates the potential danger to  the leatherworker.

THE SCRATCH AWL

When cutting a specified width from a piece of leather, the scratch awl can be used to ensure an accurate, quick result without using a pattern:

1. Place a ruler along the top edge of the work, the desired measurement on the ruler aligned with the leather’s left-hand edge. Place the awl’s point hard up against the ruler’s right-hand end (this is assuming that the ruler measurement begins at the ruler’s end). Use the awl to make a pin-prick mark on the leather’s surface.
2. Position ruler along the bottom edge, with the point of the scratch awl held against heel of the ruler, as before. Mark the surface of leather with the awl’s point. Leave awl held in this position.
3. Move the ruler and rest the bottom of its side edge against the awl point and align its top edge with the pinprick mark made previously. Cut along the line.

Fig 20a, b & c Measuring and cutting leather – quick method.

BEVELLING

PURPOSE

Bevelling is usually only required for thicker leathers. The idea is to remove the 90-degree angle from one or both sides of the leather’s cut edge so as to present a pleasantly rounded edge surface rather than a sharply angled one.

METHOD

1. Lay the leather flat on a raised surface (something like a 305×305mm/12in×12in piece of 50mm/2in thick blockboard or similar), and push the edge beveller along the edge.
2. Press hard on the leather with the other hand, which should be used to rotate and manipulate the leather as necessary to follow curves, rather than having to adjust the cutting hand too much. A continuous strip of shaved leather should appear. If the cutting tails off and breaks, start again at the point of breakage – the break will not show.

BURNISHING

PURPOSE

Burnishing consolidates hairy and fragmented cut edges, and cements these into a continuous shiny surface. Where two or more thicknesses of leather join at an edge, burnishing unifies the two edges, merging the disparate thicknesses into one. Sometimes a darker colour of solution (edge coat) is used to deliberately contrast with the main colour, or to blend with it if the grain’s surface happens to be markedly different from the hide’s cross-sectional colour. If no darkening is desired, a virtually colourless ‘paper glue’ solution achieves the purpose while only marginally darkening a light leather.

There are three types of solution used in the burnishing process:

• Specially formulated edge-coating solution, available in black, brown or tan.
• Paper glue (brown type) mixed with warm water (two-thirds water to one third gum).
• Colourless burnishing agent, produced by some manufacturers, similar to the paper glue type.

METHOD

Use a folded cloth or felt pad held in a clothes peg to apply the solution to approximately 180mm (7in) of the edge’s length, then rub briskly along this, using canvas or an edge burnishing wheel. Continue around the whole of the edge in this way.

CREASING

PURPOSE

To imprint a dark line at a predetermined distance from the leather’s edge. The creaser is heated to effect this, but since it is blunt it never tears the grain’s surface, simply presses and compresses it along a line. The purpose of creasing is largely decorative, but it also serves to strengthen and compress the loose fibres at the edge of a freshly cut piece of leather. Sometimes creasing is done on top of stitching as a way of pressing the stitch-line downwards, into the leather, so as to make the stitches appear less obtrusive. Normally used as a way of finishing off cut-edge work, both for thin and thick leathers, creasing is also sometimes used for turned-over-edge work, but this is relatively rare. For heavy leather items, creasing is normally confined to single-thickness pieces, for instance straps and sometimes flaps.

METHOD

1. Heat the blade in the flame from a blowlamp or spirit-lamp. Then use an offcut of the same leather for testing the tool’s heat: too hot and the line will appear blackened, too cool and the metal will not run smoothly across the leather’s surface. During use, heat up the creaser periodically as heat is lost.

For step creaser or adjustable creaser:

2. After heating the blade, grip the handle as shown, keeping the shoulder of the step creaser (or the other blade of the adjustable creaser) hard up against the leather’s edge. It is usual to pull the tool towards the body, exerting pressure downwards, although in some circumstances it may be found easier to push it away from the body. Often, it can be helpful to angle it, so as to maximize the advantage of the step creaser’s heel (or the adjustable creaser’s other blade) that is being supported against the leather’s edge.

Fig 21 Using the adjustable creaser.

For single creaser:

2. Mark the line initially using dividers (see below for correct use of dividers). Keeping a straight line takes practice. Instead of pulling the tool towards the body, push it forwards, away from the body.

 

There are no hard and fast rules on whether to pull or push the creaser in any given circumstances. It is down to the leatherworker’s individual preference.

Safety when using the creaser

• Remember that the tool’s end is hot,  and will burn flesh faster than leather.
• Hold the material firmly with your  other hand, ensuring that the tool will  not slip sideways.
• Extinguish the heating flame as soon  as is practical.

USING DIVIDERS

Fig 22 Using dividers to mark a measured line from the edge of the leather.

Lay the work down flat and draw the dividers along, keeping one divider arm against the leather’s edge, the other on its surface, pressed down so as to leave an impression.

TURNING OVER EDGES

After skiving (reducing the thickness of) the leather edge the requisite distance from the edge (see Chapter 4), latex adhesive is applied to the flesh-side of the edge to be turned over.

1. After applying adhesive and waiting for it to tack dry, establish a straight edge by holding a metal ruler on top of the edge to be enclosed; then lift and push up the turnover, using a bone folder.
2. Rub the bone folder along the leather held against the ruler’s edge to consolidate the turn.
3. Fold over and stick down the turnover, prior to turning the article over, stitch-marking and stitching from the other (best) side.

There are two methods for neatly finishing off square corners:

TRIMMING TO AN ANGLE

This method is used for average thickness leathers:

Fig 23 Turned-over-edge work. Angle-cutting the corner before the turn, showing the scratched grain surface of leather to be bonded.

1. Cut the corner as shown, with the distance between the angled cut line and the point of corner being approximately the thickness of the material to be folded over. Cut it oversize and fold up the corner to check for accuracy. Remove a sliver more if necessary.

2. Apply adhesive and tap up the turnover as described above, both sides of the corner, then fold it over and stick down. Use the side of the bone folder to tap against the corner to round off the sharp point and fold the small piece of leather upwards.

Fig 24 Tapping the comer of the turn with the bone folder.

Fig 25 Using the point of the bone folder to drag and stretch turned-over leather to neatly cover a corner.

3. Use the point of the bone folder to drag the corner part over any uncovered area, then to push the sides together neatly. The thinned leather will stretch to a certain extent if covering the material is difficult.

TRIMMING OFF WITH SCISSORS

This method is used for thinner-than-average leathers or rexine:

Fig 26 Trimming off excess material at the corner using scissors – for thin leathers or rexine only.

1. Do not cut the corner leather at all, but apply adhesive as usual and pull the turnover up and over and stick it down.
2. Using sharp scissors, trim off the excess material. When the cut edges are smoothed down the result should be a neatly finished corner.