The Art of Coloring Wood

Stains

There is a significant difference between the way stains color wood compared to how chemicals and dyes do the job. Stains color wood with pigments, which are particles that do not completely dissolve as dyes do.

Dyes dissolve in water the same way that salt does. If you add salt (a dye) to boiling water, it dissolves into the water and becomes an integrated part of the solution—and remains that way even after the solution returns to room temperature.

Pigments, on the other hand, are somewhat like chopped herbs in an oil and vinegar dressing. When stirred or shaken vigorously, they are suspended in the solution, but when left alone, the ingredients eventually separate and the herbs (like the pigments) settle to the bottom of the solution.

So because chemicals and dyes do completely dissolve in their carrier (typically water) they are able to color the fibers of the wood without leaving a residue of particles. Consequently, light is still able to penetrate into the pores of the wood and reflect back, enabling you to see the grain pattern with a much greater degree of clarity.

Stains, on the other hand, deposit a residue of pigment that lodges in the pores of the wood, in effect clogging the pores with color. Because this residue is opaque, and not transparent like dyes, the light is unable to penetrate through the pores and reflect back and thus the grain pattern is obscured.

The advantage of this opacity, however, is that stains are a much more appropriate colorant for outdoor projects because light does not penetrate through them as directly as it does through chemicals and dyes. Their opacity acts like sunblock on the wood, making the color more light-fast.

If given a choice, Brian usually prefers to use chemicals and dyes over stains because of the richer resolution they provide. His primary reason for using stains is if he is doing repair work on a piece that has already been stained, or if he needs to match one piece of furniture to another that has already been stained.

But let’s be honest: Many people who want to color their wood feel more comfortable using a stain because chemicals and dyes can be intimidating until—like anything else in life—you get the hang of them. And because stains dry more slowly due to their oil base, they are easier to apply because you have a longer open time and don’t have to worry as much about lap marks.

Stains are pleasant looking but there is no depth of character. The wood looks the same from any angle. There’s no chatoyance or shimmer like you get with chemicals and dyes.

1. Pigments

Like natural dyes, pigments were derived from organic materials (iron oxides in this case) and were used as colorants for centuries. Iron oxide deposits were discovered in Sienna, Italy (raw sienna, burnt sienna!) Umbria, Italy (umber!) and in France (ochre!)Cavemen learned that raw earth pigments outlasted coloring agents from animal and vegetable sources and began using the pigments to paint the walls of their caves. Appalachia is also currently a source of natural earth pigments.

Following the trajectory of natural dyes, however, pigments were also eventually made in a laboratory as well.

Because the pigments used in stains are similar to those found in house paints, you are in a sense “painting” your wood when you stain it. Unlike paint however,which typically dries to a darker shade compared to the color you see when it is wet, stains tend to dry to a lighter shade.

Another type of coloring medium you may have heard of is “Japan colors.” They are similar to artist oils in that they are very finely ground pigments added to an oil medium (boiled linseed oil) that has metallic driers, such as the conveniently named Japan Driers, added to it because otherwise the Japan colors would take much longer to dry. There are various manufacturers of Japan colors.

2. Carriers

In oil-based stains,the carrier is typically paint thinner, which is a petroleum derivative solvent. Paint thinner has two advantages over pure gum turpentine, which could also be used as a carrier. First, paint thinner is less expensive because pure gum turpentine is extracted from the pitch of pine trees, which makes it more labor intensive to produce. Second, paint thinner is slower to evaporate so it gives you a longer open time in working with the stain, which is helpful on larger projects.

Pre-Sealing the Wood

To help the wood accept the stain more evenly, you might want to pre-seal your wood with a thinned-down finish coat. This is especially important on woods that are prone to blotch because of a soft or uneven pore structure, such as maple and cherry. Even with a pre-seal coat, stain can still look blotchy on these woods, but it will most likely look dreadful on maple without it. Truth be told, Brian never stains maple or cherry.

Whereas you will still have blotch on these woods with chemicals and dyes, the blotch disappears depending on the angle from which you are looking at the wood. With stains, however, the blotch registers from any angle.

There are many effective pre-sealers or wood conditioners on the market. Any final finish coat that you thin down to a certain degree becomes a pre-stain wood conditioner, also known as a wash coat.

3. Binders

Boiled linseed oil, popularly referred to as BLO, is the preferred medium and it has driers in it to help speed up the drying process. White lead was used as a drier until the toxic health effects associated with it became known. Driers nowadays tend to be cobalt and manganese.

Two Additional Ingredients to Consider

1. Acetone

Pigment can be mixed into a small amount of acetone first to break it down somewhat before further mixing it with paint thinner, which is the true carrier.

Even though BLO by definition has driers in it, you may want to add a touch more to speed up the stain’s drying time so that you can begin putting a coat of finish on the wood. Nonetheless, you should still let the stained wood dry overnight before applying a finish coat.

The Final Color

Unlike chemicals or dyes where the color of the wood while wet reveals what the final color will look like with a coat of finish, it works differently with stains. Stains dry lighter than they appear when wet, so in order to determine the final color, you need to actually apply a coat of finish to your sample in order to determine if your stain solution is the right color intensity for your project.

However, if you have not added additional driers to your stain solution, you will have to wait longer because BLO is slow-drying and as it dries the color will continue to change. Only when the stain is completely dry can you apply a clear coat finish to see what the final color outcome will be.

To lighten a stain color, simply add more paint thinner. To darken a stain, add more pigment to the already-made solution, and this may require an additional proportion of binder (BLO). You can’t simply re-stain the wood with the same color twice because the binder component in stains (BLO) is a finish coat by itself and prevents further pigment absorption after it has already been applied to the wood. However, bear in mind that the more pigment you add to darken your stain color, the less of the grain pattern you are going to see. In effect, you begin to visually lose more of the character of the wood.

You don’t have to raise the grain before applying oil-based stains because there’s no water in them to kick up the grain.

There are water-based stains, but most people prefer oil-based because of their long open time.

How To Make and Apply a Stain:

1. Stir the pigment thoroughly into the acetone, and then add the paint thinner, stirring vigorously.
2. Add the boiled linseed oil and mix thoroughly.
3. Strain the solution through a cone strainer. You might end up with a lot of pigment remaining in the bottom of the filter. Push as much of these solids as you can through the filter and don’t worry about the rest. There will always be some pigment that doesn’t break down in the thinner.
4. Stir, stir, stir.
5. Immediately before applying the stain to your project, stir it well once again. Keep stirring it as you continue applying it.
6. Use a high-quality natural brush because it holds more material so that you don’t have to make as many trips back to the bucket.
7. Never rest your brush inside the solution because it will absorb pigments that have settled to the bottom of the container, resulting in uneven color when you resume staining the wood.
8. Keep a wet edge as you apply the solution.

Recipe for Alder with Half Dye and Half Stain

The stain and dye colors have been custom matched so that the bottom half of the sample is dyed and the top half is stained to show the difference between the grain pattern being obscured with stain and more visible with dye.

Dye

4 oz. hot distilled water

4 oz. cold distilled water

½ tsp Arti Dye #790 Brown

¼ tsp. Arti Dye #1605 Light Oak

A smidgen ( tsp) of Transtint Red

Slowly stir ½ teaspoon of Arti Dye #790, ¼ teaspoon of #1605 and a smidgen of Transtint Red into four ounces of hot distilled water. Mix thoroughly until dissolved and then slowly stir in four ounces of cold distilled water. Strain the solution into a clean container. When it reaches room temperature, apply and then wipe the excess solution with a clean rag.

Stain

2 oz. acetone

3 tsp. Red Oxide Dry Earth Pigment

1 tsp. Burnt Umber Dry Earth Pigment

1½ oz. BLO

2 oz. Paint Thinner or pure gum turpentine

¼ tsp. Japan Drier

Mix and apply according to directions above.

Alder, top-half stained and bottom-half dyed.

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