Editing Silk (section)

==Cultivation==
[[File:Thai man spools silk at Jim Thompson House photo D Ramey Logan.jpg|thumb|Thai man spools silk]]
[[File:Bombyx mori Cocon 02.jpg|thumb|[[Pupa#Cocoon|Cocoon]]]]
Silk [[moth]]s 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 {{convert|1|mi|km|spell=in}} of filament and is completely encased in a cocoon. The silk farmers then heat the cocoons to kill them, leaving some to [[metamorphosis|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.<ref>Gleason, Carrie (2006) ''The Biography of Silk''. Crabtree Publishing Company. p. 12. {{ISBN|0778724875}}.</ref>