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Lac is the scarlet resinous secretion of the insect Kerria lacca. This important animal is also known by some junior synonyms such as Laccifer lacca, Carteria lacca and Tachardia lacca. However, the oldest name Kerria lacca is back in current use. Kerria lacca belongs to the lac insect family Kerriidae, one of some 28 families of scale insects and mealy bugs belonging to the superfamily Coccoidea, a large group of about 8000 described species of plant sucking insects. Thousands of these tiny insects colonize branches of suitable host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as sticklac.

The harvested sticklac is crushed and sieved to remove impurities. The sieved material is then repeatedly washed to remove insect parts and other soluble material. The resulting product is known as seedlac. The prefix seed refers to its pellet shape. It is used in violin and other varnish and is soluble in alcohol. This type of lac was used in the finishing of 18th century fowling guns in the US. Seedlac which still contains 3-5% impurities is processed into shellac by heat treatment or solvent extraction.

Lac production is found in Assam and other parts of North-East India, Bangladesh, Myanmar, Thailand, Laos, Vietnam and parts of China. It is also found in Mexico.

Kerria lacca can be cultivated on either cultivated or wild host trees.

• In India the most common host trees are
  • Dhak (Butea monosperma)
  • Ber (Ziziphus mauritiana)
  • Kusum (Schleichera oleosa)
• In Thailand the most common host trees are
  • Rain tree (Samanea saman)
  • Pigeon pea (Cajanus cajan)
• In China the common host trees include
  • Pigeon pea (Cajanus cajan)
  • Hibiscus species
• In Mexico
  • Barbados nut (Jatropha curcas)

The use of lac dye goes back to ancient times. It has been used in India as a skin cosmetic and dye for wool and silk. In China it is a traditional dye for leather goods. The use of lac for dye has been supplanted by synthetic dyes. It is used in medicine as hepatoprotective and antiobesity drug.

It has a mention in the ancient Vedic book called the Manusmrti, or the 'Laws of Manu'. This book is the source of all the laws regarding caste in India. It lays down who can eat with whom, who can marry whom, who can touch whom; and it also lays down how those who infringe those laws should be punished. Thus, for example, it is decreed: "XII. 4. If the shudra [a member of the labouring caste, or an Untouchable] intentionally listens for committing to memory the Veda, then his ears should be filled with molten lead and lac; if he utters the Veda, then his tongue should be cut off; if he has mastered the Veda his body should be cut to pieces."

Shellac (the refined form of lac) is used in several industrial applications, such as:

• Surface coatings
• Textiles
• Printing
• Cosmetics and pharmaceuticals
• Adhesives
• Electrical industry

Shellac was also used to manufacture 78 rpm phonograph records from 1897 until the 1950s, when vinyl plastic, being much more durable, was used instead.

• http://www.szgdocent.org/resource/ff/f-arth3a.htm
• http://www.beadnshop.com/lac-kashmiri-beads/ Beads and other products produced with the help of lac. Manufacturing process and information on site.
• [http://www.jatropha.de/ The Jatropha Website, for production in Mexico

Picture of lac insect here [1]; drawing of insect, its larva and a colony here[2]