What are the differences between stains and dyes?
Very simply put: With stains, the pigment tends to remain on the surface of the wood and lodge in the pores, while dyes penetrate deeply and color the wood from within.
Dyes are colorants that are usually mixed in a carrier vehicle (solvents) such as mineral spirits, water or alcohol. The dyes used in woodworking are characterized as transparent, as they bring about color changes in wood without obscuring the figure. The molecular size of the dye particles is so small they allow light to pass through virtually unhindered. In simple terms, dyes are typically soluble salts. Once mixed with their proper solvent, dye crystals separate into individual molecules, which are vastly smaller than ground up pigment particles. Thus, dye can get into spaces where pigments cannot.
Water-based dyes are said to be less susceptible to fading (more lightfast) than alcohol-based dyes, while oil-based dyes fade the fastest. Alcohol-based dyes can be used to make toners and shaders by adding them to lacquer or shellac. By then gently spraying on very thin layers, you can blend unlike areas together or change the overall hue while retaining as much clarity as possible.
Stains are really nothing more than very thin oil or waterborne paints. That being said: dye stains are typically comprised of only dye and a carrier vehicle (solvents), stains are comprised of pigment, a carrier vehicle (solvents) and a binder. Using a thin varnish (oil-based) or acrylic latex (waterborne) as a binder, ground particles of natural and synthetic minerals are added to make stains. Stains should be stirred often to insure an even dispersion of pigment because the particles tend to settle on the bottom.
A special case in the stain family is the gel stain. As the name implies, gel stains have a much thicker consistency than liquid stains. The thickness of a gel stain depends on the brand you use. Some have the consistency of petroleum jelly, while others are more like peanut butter.
Because gel stains lie more on a wood surface instead of soaking into it, they more uniformly color porous and nonporous areas, unlike the light and dark blotches you sometimes get with liquid stains. Gel stains therefore produce a much more uniform color. Also, because they don’t run or splatter, they’re especially handy for applying to vertical surfaces.
The reason gel stains lie more on a wood surface instead of soaking into it is simple. There’s less solvent in a gel stain. Because the solvent of a stain carries the color into the wood, the gel stain doesn’t penetrate as deeply.
One other nice thing about gel stains is you don’t have to keep stirring them as you work. Because they are thicker, the color pigment stays suspended instead of settling out in the bottom of the can. This means you get a consistent color from the top to the bottom of the can.
Differences between stains and dyes
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