Shellac

Shellac is a resinous substance secreted by the lacquer scale insect that accumulates on the branches of the host tree. Mainly in South and Southeast Asia, and here especially in India and Thailand, shellac used to be produced in large quantities. The annual production amounted to about 50,0000 tons. To harvest one kilogram of shellac, you need about 300,000 lacquer scale lice.
For gilders, shellac is mainly used as a universal barrier agent for absorbent substrates or as a protective coating. In painting techniques, the use of shellac is mostly limited to the execution of historical techniques. Shellac is only suitable for indoor use.