A hard, transparent protective finish used with lumber. Traditionally, varnishes have been made of a drying oil, a resin, and a solvent. Usually they are glossy, but satin and mattE finishes are available. They dry by the evaporation of the solvent, or by oxidation of the oil. Resin varnishes dry immediately; however, acrylic and water-borne varieties take time to cure. Oil, polyurethane and epoxy varnishes undergo an extended curing process.
The main constituents of traditional varnish are: