A yellow resin formed from secretions of the LAC insect, used in making varnish.<br><br>Lac is a resinous substance secreted by the lac insect, and found on trees in southeast Asia. It is melted into plates (which resemble shells) and used in the manufacture of a varnish which provides a golden translucent finish that darkens with age. Shellac has been used most frequently as a coating on wood, but also on bronzes and plaster cast. It can be toned with various pigments. Shellacs are available with a matte, semi-gloss, or glossy finish.Also see lacquer and polyurethane.