Varnish is the solution of resins or resinous substances like amber, copal, shellac, gum resin etc. in solvents like oil, turpentile, alcohol etc. Depending upon the solvents used varnishes are classified as, oil varnishes, turpentilevarnishes, spirit varnishes and water varnishes.
The desirable characteristics of an ideal varnish are
1. It should give glossy surface.
2. Should be durable.
3. It should dry rapidly after application.
4. It should not develop cracks after drying.
5.It is commonly used on wooden surfaces.