lac

 

resinous exudation from the bodies of females of a species of scale insect (Tachardia lacca), from which shellac is prepared. India is the chief source of shellac, although some is obtained from other areas in Southeast Asia. The insects feed on the sap of the twigs of certain tropical trees, some of which are cultivated for this purpose. The resinous secretion hardens upon exposure to air and forms a protective incrustation around the female and young, which are thus held fast to the twigs. The twigs are scraped to remove the incrustation; this crude lac material is known as stick lac. If the stick lac is crushed, the wood splinters and other foreign materials removed, and the red coloring matter produced by the insects dissolved out, the residue when dried is seed lac. Seed lac is melted, filtered, and stretched into thin sheets, which are broken into flakes when cool. Orange-colored shellac is made from these flakes by dissolving them in alcohol. White shellac is made from bleached lac.

Lac is a resinous substance produced by insects.

Lac may also refer to:

• Lac, a district in the canton of Fribourg, Switzerland
• Laç, a city in Albania
• Lac Prefecture, Chad
• Lac operon, for the metabolism of lactose in bacteria such as E. coli
• Lac, Lacerta per standard astronomical constellation abbreviation
• Lạc, the Vietnamese term for Luò, one of cultural grouping of the Yue peoples of ancient China
• L.Ac., Licensed Acupuncturist, see acupuncture

See also

• LAC
• Lakh, a word meaning 100,000 in the Indian numbering system
• Cadillac, American automotive manufacturer
• lack

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