What is lac?
Lac is a natural, biodegradable, non-toxic, odorless, tasteless,
hard resin and non-injurious to health.
Lac is, in fact, a resinous protective secretion
of tiny lac insect, Kerria lacca (Kerr) which belongs to the
family Tachardidae in the super family Coccoidea of the order
Hemiptera. The lac insect is a pest on a number of plants
both wild as well as cultivated. The tiny red–colored larvae of
lac insect settle on the young succulent shoots of the host
plants in myriads and secrete a thick resinous fluid which
covers their bodies. The secretion from the insects forms
a hard continuous encrustation over the twigs.
The encrusted twigs are harvested and the
encrusted twigs scraped off, dried and processed to yield the
lac of commerce which is regarded as Non Wood Forest Product (NWFP)
of great economic importance to India.
Ari Lac And Phunki Lac
If lac crops are harvested by cutting down the
lac bearing twigs a little before the larval emergence, that lac
is known as ARI LAC (immature lac) or after the emergence is
over, that is called PHUNKI LAC (empty lac).
Lac And Its Forms
Stick lac: The lac encrustations is
separated by knife or broken off with finger from the twig of
host plants and is known is STICK LAC or CRUDE LAC or RAW LAC.
Seed lac: The stick lac, after grinding
and washing, is called SEED LAC or CHOWRI.
Shellac: The manufactured product
prepared from stick lac after washing and melting, which takes
the form of yellow colored flakes, is called SHELLAC.
Button lac: After melting process, lac is
dropped on a zinc sheet and allowed to spread out into round
discs of about 3” diameter and 1/4” thickness is called Button
Garnet lac: It is prepared form inferior
seed lac or kiri by the solvent extraction process. It is dark
in color and comparatively free from wax.
Bleached lac: It is a refined product
obtained by chemical treatment. It is prepared by dissolving
shellac or seed lac in Sodium carbonate solution, bleaching the
solution with Sodium hypochlorite and precipitating the resin
with sulphuric acid. Bleached lac deteriorates quickly and
should be used within 2-3 months of manufacture.