Varnish

Varnish, solution of resin that dries to form a hard, transparent film. It is widely applied to wood, metal, and masonry to improve surface properties without changing appearance. There are two main types: spirit varnishes, consisting of natural or synthetic resins dissolved in a volatile solvent such as alcohol, and oleoresinous varnishes—more resistant to heat and weather—which are mixtures of resins and drying oils dissolved in turpentine or a petroleum oil. Lacquer, the original wood varnish, is the sap of the varnish tree.

See also: Resin.