When it comes to home improvement, staining doesn’t get as much attention as painting. It’s a humbler art, really: Whereas paint transforms the color of a surface, leaving no trace of its previous hue, stain is typically used to accent the natural beauty of wood. Its purpose is to bring out the best in what’s already there, and with enough practice, you’ll be able to make the wood in your house as gorgeous as a perfectly painted wall. Wood stain consists of dye or pigment in a solvent (or “vehicle”) such as water, alcohol, petroleum distillate, or lacquer, to name a few examples. It’s used to give wood a distinctive color – to beautify it without hiding the appearance of its grain.
Though pigment and dye differ in their chemical makeup, either may be the best choice for a given project. Much depends on the wood as well as environmental factors, especially if the surfaces to be stained are outside. Dye is made up of tiny crystals that dissolve in the vehicle of a stain, and it can penetrate wood’s cellular structure. For this reason, it’s both more transparent and more natural-looking than pigment. Particles of pigment are merely suspended in the vehicle, since they’re much larger than dye crystals. Pigments are made of inert compounds, either natural or synthetic. Due to dye’s small particle size, it can color fine-grained wood, like cherry or maple, while the pores of such species are too small for pigment particles to adhere to. Pigment-based stains always include a binder that helps the colorant attach to wood. The majority of commercial stains include both pigment and dye. Most have more pigment, which means they need a binder – often one that contains a lot of curing oil, which helps make the stain dry slowly. The amount of time that a stain spends on a segment of wood usually determines how dramatic the stain’s effect is. Whereas pigment is opaque, dye is translucent. (Gel stains, like paint, achieve little penetration into wood’s cells.) Water-based stain is more eco-friendly than the oil-based equivalent, and it cleans up simply, with soap and water. It also has a shorter drying time, however, so it can be hard to apply evenly. It also tends to raise the wood grain, but it won’t do as much if you get there first. “Pre-wet” the wood in question, wait for it to dry, and then sand it. The stain’s wood-raising effects will be considerably reduced. On that note: Sanding wood with sandpaper that’s finer than 150 grit is a bad idea if you plan to apply pigment stain. Due to its sizable particles, pigment must attach to irregular features in wood, such as scratches or cell surfaces. Making a piece of wood too regular more or less ensures a frustrating staining process. Unlike pigment stain, dye stain often comes in powder form. After being dissolved in water, it achieves a significantly deeper color in wood than pigment can, and it doesn’t hide the grain as much. In addition, dye stain can be custom-blended, or even color-corrected after the initial application. Dye stain does have its downsides. It’s susceptible to fading in the sun, whereas pigment holds its color no matter what. Metalized dye, premixed with alcohol and a chemical that slows drying, is more colorfast than regular dye. Then there’s oil-soluble dye, which can be used to adjust the color of an oil stain and deepen its penetration, or to add color to an oil-based clear finish. Paint contains a combination of pigment, solvent, and binder, but stain has much more pigment, and not nearly as much binder. While a binder may create a film on wood, varnish, which lacks pigment entirely, is generally applied after stain to produce a more complete surface coating. Binders go below the surface of the wood, whereas pigment remains near the top. Siding stain has a higher viscosity than stain meant for interior wood. Though it otherwise resembles paint, it does not form a hard film. Siding stain protects wood against many ambient threats, including UV radiation, water, fungus, and insects. How easy it is to apply stain depends on the nature of the substrate and the stain, and also upon environmental conditions. In general, aged wood accepts stain much more readily than its fresh-cut counterpart, and wood that’s been exposed to paint strippers, solvents, and similar substances is easier to stain, since its grain is more open. End grain and bias-cut grain are inherently more absorbent when it comes to stain. For obvious reasons, it’s more difficult to work with fast-drying stain in the hot sun, and harder to use slow-drying stain in cold, wet weather. Some wood leaves the mill with a sealant, which can prevent staining. Fortunately, such sealant can be sanded off with relative ease. Sanding is also a helpful way to even out stain absorption on a piece of wood, and garnet sandpaper is the kind to use. Like painting or any other kind of aesthetic improvement, staining wood has a learning curve. Trying different kinds of stains with different species of wood is part of the process, and experimenting can yield interesting, and sometimes lovely, results. If the wood in your home is one of its visual highlights, see if you can make it shine even brighter with the right stain.