How is silk made?
We live in the Age of Science and every day more and more of our textile materials are woven. from fibers of man made plastics. BLit the era of nylon and orlon, rayon and dacron is but a blink in the long history of human apparel. Through most of this long time, mankind has woven his textiles from threads and fibers made by nature. Silk making is a gift of the world of insects.
Many insects have special glands for spinning silken threads. Most of the moths spin silken cocoons around themselves while they sleep through their pupa stage of development. The tent caterpillars spin themselves airy shelters of silken thread. Perhaps the finest and strongest of silken threads is spun by the spider who uses her silk to build a trap for flies.
These silken threads, however, are not sturdy enough to be woven into textiles for human clothing. So far as we know, the only insect to spin a thread suitable for this purpose is the silkworm and this fussy, pampered little caterpillar has been in captivity for thousands of years. Like our pet rabbits, this creature has been cared for by human beings for so long that he could no longer survive in the wild state.
The adult of the silkworm is a fat, furry moth but this Ls the fourth and final stage of its complicated life. It starts life as a pale little egg which, in a few days, hatches into a wormy little caterpillar. In about five days, the caterpillar has eaten enough to burst its skin. The feeding is then resumed and altogether the silkworm molts its skin four times.
The larva or caterpillar stage is then over and the silkworm gets ready for its pupa stage. This is when it spins and spins a thread of silk perhaps half a mile long and winds it around its body to form a cocoon. It is this thread of silk and thousands like it which is used to weave silken cloth. A silkworm producer may start with about one ounce of egg.; which, with luck and a great deal of patient care, may eventually yield about 12 pounds of raw silk. The fussy silkworms must be kept warm u:nd dry and very quiet. They live on shallow trays lined with paper and their quarters must be carefully cleaned every day. The fussy little warms are at their fussiest in the matter of diet, They will eat r. oijhing but mulberry leaves and these mulberry leaves must be the freshest and the most tender.
Patience is rewarded when the silkworms reach the pupa stage and each weaves its silken cocoon. A few cocoons are allowed to hatch into moths which will lay more eggs. Most of the cocoons are gently warmed to destroy the living insects inside. The long threads of sil=c are unwound and sold as raw silk which will be washed and combed and twisted into fibers suitable for textile weaving.