Varnishes are also applied over wood stains as a final step to achieve a film for gloss and protection. Some products are marketed as a combined stain and varnish.
http://en.wikipedia.org/wiki/Varnish

From Dick Blick Art Materials - find spray and brush-on varnishes that suit every fine art and craft need, for paintings, drawings, sign-making, screen-printing, and more.
http://www.dickblick.com/categories/varnishes/

varnish, homogeneous solution of gum or of natural or synthetic resins in oil (oil varnish) or in a volatile solvent (spirit varnish), which dries on exposure to air, forming a ...
http://encyclopedia2.thefreedictionary.com/varnishes

Grizzly Industrial, Inc.: Online Ordering of Woodworking and Metalworking Machinery and Tools ... S ince our inception in 1983, Grizzly Industrial Inc. has grown into one of the ...
http://www.varnishes.com/

Alchemist, Inc - Makers of historical and traditional amber resin and natural resin-based varnishes and painting mediums. Don Fels has rediscovered the Old Master\'s secret:
http://www.ambervarnish.com/