Shellac, commercial resin marketed in the form of amber flakes, made from the secretions of the lac insect, a tiny scale insect, Laccifer lacca.

Shellac is a natural thermoplastic; that is, a material that is soft and flows under pressure when heated but becomes rigid at room temperature.

This property makes it useful either by itself or in combination with such fillers as flaked mica and asbestos in manufactured molding compositions, used for producing molded articles such as buttons.