Shellac's a resin secreted by the female lac bug to form a cocoon, on trees in the forests of India and Thailand. It's processed and sold as dry flakes (pictured at right), which are dissolved in denatured alcohol to make liquid shellac, which's used as a brush-on colourant, food glaze and wood finish much like a combination of stain and polyurethane. Shellac functions as a tough all-natural primer, sanding sealer, tannin-blocker, odor-blocker, stain (pigment), and high-gloss varnish. Shellac w… (More on Shellac)