Shellac

The term shellac is derived from shell-lac (the word for the refined lac in flake form) but has come to refer to all refined lac whether in dry or suspended in an alcohol-based solvent.

Shellac is primarily used as a wood sealer and finisher today. It has the great advantage of being soluble in ethyl or denatured alcohol and an environmentally safe solvent. Alcohol solvents also render shellac a quick-dry—shellac coatings on wood generally dry in about 45 minutes, as opposed to oil finishes which take many hours to dry. In addition, shellac does not fade in sunlight or oxidize over time. However, shellac has a limited shelf life and may not dry properly if it has exceeded the shelf life recommended by the manufacturer. This shelf life may be as short as six months or as long as three years depending on the manufacturer's additives.

Industrial uses for shellac include floor polishes, inks, grinding wheels, electrical insulation, and leather dressings. This natural, resinous sealer is non-toxic and is Federal Drug Administration (FDA) approved for use to coat candies, pharmaceuticals, fruit, and baby and children's furniture.

Shellac is available at most hardware or paint stores in clear or white shellac or orange shellac, which imparts an orange-red tint to natural wood. Other tints derive their color, not from dyes or bleaches, but because of the tree to which the lac bug has attached itself—the sap affects the color of the bug secretions thus altering the color of the refined shellac. Shellac may be applied to wood, over varnish, paint, glass, ceramics, even plastic with remarkable adherence, but it cannot be used under synthetic sealers such as polyurethane.