Shellac

Some of the many different colors of shellac
Shellac in alcohol

Shellac (/ʃəˈlæk/)[1] is a resin secreted by the female lac bug on trees in the forests of India and Thailand. Chemically, it is mainly composed of aleuritic acid, jalaric acid, shellolic acid, and other natural waxes.[2] It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odour-blocker, stain, and high-gloss varnish. Shellac was once used in electrical applications as it possesses good insulation qualities and seals out moisture. Phonograph and 78 rpm gramophone records were made of shellac until they were replaced by vinyl long-playing records from 1948 onwards.[3]

From the time shellac replaced oil and wax finishes in the 19th century, it was one of the dominant wood finishes in the western world until it was largely replaced by nitrocellulose lacquer in the 1920s and 1930s. Besides wood finishing, shellac is used as an ingredient in food, medication and candy such as confectioner's glaze,[4] as well as a means of preserving harvested citrus fruit.[5]

  1. ^ "Shellac". Cambridge Dictionary. Retrieved 19 October 2020.
  2. ^ https://www.researchgate.net/publication/255771177_Natural_resin_shellac_as_a_substrate_and_a_dielectric_layer_for_organic_field-effect_transistors/figures?lo=1 Chemical composition of Shellac
  3. ^ Read, Oliver; Welch, Walter L., From Tin Foil to Stereo, U.S.A., 1959
  4. ^ Lee, John. "The Strange Ingredient Used To Make Jelly Beans Shiny". TastingTable. Static Media.
  5. ^ Mcguire, Raymond G.; Hagenmaier, Robert D. (1 November 2001). "Shellac Formulations To Reduce Epiphytic Survival of Coliform Bacteria on Citrus Fruit Postharvest". Journal of Food Production. 64 (11): 1756–1760. doi:10.4315/0362-028X-64.11.1756. PMID 11726155.