How to Use Stain and Varnishes for Wood Finishing


Stain and varnishes are important components for completing a woodwork project. But do you know their differences and why you should consider using them? Here is a simple guide on understanding the key elements making stain and varnish unique, the variety of wood finishes and how they perform, as well as how to use varnish for finishing. Having this knowledge can help you with your next home remodeling projects if you like to get handy.


Varnish is a popular, clear coat for wood with a hard protecting film that not only protects but also helps retain natural wood tones with a glossy finish. While varnishes perform better on wood, they can also be applied to other substrates and offer the same aesthetic and protective benefits.

Composition of Varnishes

Varnish is essentially a type of paint without the element of color. Most of them are made from synthetic, polyurethane water-and oil-based resins. They are much like oil paints. However, polyurethane clear coat varnishes are known to produce fumes that can have adverse effects on a person. For this reason, eco-friendly varnishes such as acrylic are increasingly becoming common although they are water-based.

The composition of varnishes is important particularly when it comes to environmental and health impact. Look for odor-free and low VOC paints that you can also use on your baby crib. Here are three main components of varnishes.

  • Resins: Like paints, varnishes consist of resin which adds strength to the layer of finishing. Natural resin is obtained from different sources including trees, flowers, shrubs, insect secretions as well as synthetic resins. The type of resin used in varnish can significantly affect the properties of the varnish such as adhesion, color and strength.
  • Drying Varnish Oils: This is the component that cures and dries to form the protective film offered by varnish. The composition ratio and types of oil mixed with resin will have a bearing on the varnish properties. You can choose from a tough brittle varnish or a flexible option, suited ideally for outdoor application. Remember that the glossiness of the wood will depend on the quantity and type of oil.
  • Solvent: Or thinner is the element that thins the oils and resins allowing the varnish to flow more easily and dry faster. There are different types of thinners including water, which can only be used for water-based varnishes.

Wood Stains

Unlike varnishes which often lack pigmentation, wood stains are colored like regular paints and they lack protective coating because they are absorbed easily. Generally, a wood stain is made up of three components, like paints.

    • Pigment: This is essentially the color component in a stain. The color can either be achieved with either a suspended pigment or dyes dissolved in the solvent. A suspended pigment forms large molecules that cannot infiltrate a wood structure creating an opaque finish. The most stain colors are browns and natural wood grains though there are other more colorful options for specific applications.
    • Solvent: This is an oil-based ingredient that helps to carry pigment and dye into the substrate; It helps the stain adhere properly. When the solvent evaporates it leaves the color to strengthen.
    • BinderThis makes a small portion of the stain, but it still an important ingredient that chemically holds the pigment into the substrate.

Stain and varnish should be properly mixed to ensure uniform color on a substrate. When used together, the stain offers the pigment while a varnish provides a protective coating. Though regular paints offer these two benefits, however, paints only cover the surface, where both stain and varnish sits deep into the surface.