Shellac is a natural resin secreted onto trees by the female lac bug. It is processed and sold as dry flakes or refined into granular powders. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odor-blocker, stain, and high-gloss varnish. Shellac is also used in electrical applications due to its insulating properties. It is also used in many food applications.