Liquitex-Gloss Medium & Varnish. The workhorse of the Liquitex mediums range. Gloss Medium & Varnish is an all-purpose medium that performs two functions. It can be used as a varnish and/or a fluid gloss medium. It improves adhesion of paint film and increases color depth, intensity, and gloss. It can also be used as a non- removable varnish to protect the surface and establish an even gloss sheen. This package contains one 4 ounces of Gloss Medium & Varnish. Conforms to ASTM D 4236.