Varnish is a common wood finish that makes the surface underneath resistant to heat, moisture and several solvents. It is created from a resin, usually alkyd or polyurethane, dissolved in a solvent with drying oil. Specific oil types, such as linseed oil, soybean oil or tung oil are used to dissolve the resin in a bid to cure it when exposed to air.
Varnish is usually clear and is mostly applied to untreated wood or wood that has been stained. As it dries, the varnish forms a protective layer over the wooden structure it has been applied to, giving it additional protection.
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Lacquer is a clear nitrocellulose dissolved in a fast drying solvent. It is applied to wooden furniture, floors and other structures to create a clear protective film over them, while allowing the beauty of the wood underneath to show through. There are also lacquers that are stained with pigment.
Lacquer does not adhere to formerly polyurethaned or varnished finish. It provides a really hard finish that makes the wood underneath resistant to damage from moisture, alkalies and acids.
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