Silk
Silk moths lay eggs on specially prepared paper. The eggs hatch and the caterpillars (silkworms) are fed fresh mulberry leaves. After about 35 days and 4 moltings, the caterpillars are 10,000 times heavier than when hatched and are ready to begin spinning a cocoon. A straw frame is placed over the tray of caterpillars, and each caterpillar begins spinning a cocoon by moving its head in a pattern. Two glands produce liquid silk and force it through openings in the head called spinnerets. Liquid silk is coated in sericin, a water-soluble protective gum, and solidifies on contact with the air. Within 2–3 days, the caterpillar spins about 1 mile of filament and is completely encased in a cocoon. The silk farmers then heat the cocoons to kill them, leaving some to metamorphose into moths to breed the next generation of caterpillars. Harvested cocoons are then soaked in boiling water to soften the sericin holding the silk fibers together in a cocoon shape. The fibers are then unwound to produce a continuous thread. Since a single thread is too fine and fragile for commercial use, anywhere from three to ten strands are spun together to form a single thread of silk.
History of silk
She then had the idea to weave some of it, so she kept some for herself. Having observed the life of the silk worm on the recommendation of her husband, the Yellow Emperor, she began to instruct her entourage in the art of raising silk worms, sericulture. From this point, the girl became the goddess of silk in Chinese mythology. Silk eventually left China via the heir of a princess who was promised to a prince of Khotan. This probably occurred in the early 1st century AD. The princess, refusing to go without the fabric that she loved, would finally break the imperial ban on silk-worm exportation.