The purpose of paints is to preserve the wood by covering it with an opaque material. Paints are usually composed of white lead and zinc oxide and coloring materials mixed or thinned with raw or boiled linseed oil. Turpentine is also used for thinning and as a drying agent.

Paint must be well brushed out so that a thin film may result.

In painting (1) Cover the knots with shellac, or the oil of the paint will be absorbed through two or three coats and a discoloration result. (2) Put on a prime coat. This coat should be mixed as thin as it can be and still not "run" when applied to vertical surfaces. (3) Fill the nail holes with putty. Sand lightly if a smooth finish is desired. (4) Apply two or three coats of paint thin enough to flow freely but thick enough to cover well and not "run."

The second coat is given a little more than the usual amount of turpentine that a "flat effect" may prepare the way for the final gloss coat. If the last coat is to be dull, turpentine is used in it as well as the second. Oil causes gloss, turpentine causes a dull or flat effect.