Beadboard—large, thin sheets of wooden wall paneling—can be painted or stained to any color desired, just as you would stain any other type of wood. While beadboard, another name for wainscoting, is most often installed on the lower half of walls to create a decorative look, it can also be installed over entire walls or a ceiling as well. Although beadboard can be stained after it's been applied to a wall, it is easier to stain the paneling before installing it.
Move the beadboard outdoors or into a garage. Lay a plastic tarp flat on the ground and place the beadboard on top of it. If the beadboard is already installed on a wall, remove the bottom molding with a crowbar, then lay the plastic tarp on the floor under the beadboard.
Sand out any scratches or dents in the beadboard using fine-grit sandpaper, such as 200 grit. Sand only in the direction of the wood, which in the case of beadboard is up and down. Wipe down the entire surface with a towel to remove any dust.
Apply a thin coat of oil-based wood conditioner to the entire surface of the beadboard using a paintbrush. Wood conditioner seals the beadboard, which makes the final stain appear smoother and more uniform. Allow the wood conditioner to dry completely before proceeding.
Open the can of oil-based stain and stir it well with a paint stirrer to mix the pigments.
Apply the stain to the beadboard using a natural-bristle brush. Move the brush up and down in the direction of the wood grain.
Wipe the entire surface of the beadboard lightly with a clean rag to remove excess stain. Do not press down on the rag; simply drag it lightly across the wood surface.
Allow the stain to dry completely and apply a second coat if a darker stain finish is desired.