Shellac is a natural resin that has been used for centuries across various industries. It is indeed a product of insects, and the only known commercial resin of animal origin. This substance begins its journey in the forests of certain tropical and subtropical regions, primarily India and Thailand.
The Lac Insect and Its Secretion
Shellac originates from the resinous secretion of the tiny lac insect, most commonly Kerria lacca (Laccifer lacca). These scale insects, related to aphids and mealybugs, are found on specific host trees. The female lac insect is the primary producer of this resin.
The lac insect feeds on tree sap, chemically transforming it into a resin. This resin is then secreted through pores, forming a protective, shell-like covering over the insects and the twigs they inhabit, shielding their larvae from the environment.
From Tree to Product
The journey of shellac from the host tree to a usable product begins with harvesting the resin-encrusted branches, known as “sticklac.” This raw material contains resin along with impurities such as bark, leaves, and insect debris. The sticklac is then crushed and sieved to remove larger impurities.
Further processing involves washing the crushed material to remove remaining foreign matter, resulting in “seedlac.” This seedlac is then refined into commercial shellac flakes. Refining occurs through heat treatment, where the resin is melted and strained, or through solvent extraction, commonly using alcohol, which leaves behind impurities.
Common Uses of Shellac
Shellac’s unique properties make it suitable for a wide range of applications. Historically, it has been a prominent wood finish, particularly in traditional “French polish” techniques, providing a glossy and protective layer. It acts as a sealant and can enhance the natural grain of wood.
In the pharmaceutical industry, shellac is used as a coating material for tablets and capsules, often as an enteric coating to protect drugs from stomach acid or to mask unpleasant tastes. Its use in confectionery is widespread, where it functions as a glazing agent, often listed as “confectioner’s glaze,” to give candies and chocolates a shiny, smooth finish. Shellac also serves as a protective coating for some fruits, helping to reduce moisture loss and extend shelf life. Shellac finds application in cosmetics, such as in hair sprays, mascaras, and nail polishes, due to its film-forming and binding capabilities.
Shellac and Dietary Considerations
Given its insect origin, shellac raises dietary and ethical questions. Shellac is generally not considered vegan because its harvesting involves the collection of the lac insects themselves. Vegans typically avoid products containing shellac due to these ethical concerns.
For vegetarians, the classification of shellac can be less clear-cut. While some vegetarian societies have historically considered shellac acceptable, others now do not, aligning more closely with vegan principles due to the direct animal involvement in its production. The process of obtaining shellac can result in the death of many insects. For those seeking to avoid animal-derived ingredients, alternatives such as carnauba wax or other plant-based coatings are available for similar applications.