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Shellac.
Shellac is a brittle or flaky secretion of the lac insect Kerria lacca, found in the forests of
Assam and Thailand.
Freed from wood it is called "seedlac".
Once it was commonly believed that shellac was a resin obtained from the wings of an
insect found in India.
In actuality, shellac is obtained from the secretion of the female insect, harvested from the bark of the trees where
she deposits it to provide a sticky hold on the trunk.
Shellac is a natural polymer and is chemically similar to synthetic polymers, thus it is considered a
natural plastic.
It is soluble in various organic solvents. When dissolved in alcohol, typically blends
containing ethanol and
methanol, shellac yields a coating of superior durability and hardness.
It is used in the traditional "French polish" method of finishing furniture, and fine viols and guitars.
Until the advent of Vinyl in 1938, phonograph records were pressed from shellac compounds until
about 1950.
Sheets of Braille also used to be coated with shellac to help protect them from wear
due to being read by hand.
Shellac is edible and it is used as a glazing agent on pills and candies.
Shellac is now considered obsolete as a molding compound, but its use in industries continues
as there are
no synthetic or natural substitutes in a number of processes. For examples, it is used as an outer fruit coating to
prevent post-harvest decay (e.g. apples); in dental technology it is used in the production of custom impression
trays; it is used in the optical trade.
AND it is used by many cyclists as a protective and decorative coating for their handlebar tape. |

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