Since the other Sara’s on vacation and I miss her, I thought I’d do a Sara post, complete with Wikipedia citations. If you’ve ever wondered why silk is so expensive, read on:

Silkworm Cocoons in Basket

Sericulture: the production of cultivated silk

  1. Silk moths lay eggs on specially prepared paper.
  2. Eggs hatch and the caterpillars are fed fresh mulberry leaves.
  3. After about 35 days and 4 moltings, the silkworms are 10,000 times heavier than when hatched – they are now ready to begin spinning a cocoon.
  4. A straw frame is placed over tray of silkworms – they begin spinning cocoons by moving their heads in a figure 8.
  5. Liquid silk, coated in sericin, is produced in 2 of the silkworm’s glands, which is forced through spinnerets.

    • Sericin: water-soluble protective gum
    • Spinnerets: openings in silkworm’s head

  6. As this liquid silk comes into contact with the air, it solidifies.
  7. Within 2-3 days, the silkworm will have spun 1 mile of filament and will be completely encased in a cocoon.
  8. After this entire process, the silkworm metamorphoses into a moth, but is usually killed by heat before it reaches the moth stage – any silkworm reaching the moth stage is used for breeding the next generation of silkworms.” (from Wikipedia)

This process was a closely guarded Chinese secret for centuries until it eventually made its way to Thailand and other parts of Southeast Asia around the first century AD. Apparently, it takes about 3000 cocoons to make just one yard of silk. This is why some vegans and animal rights activists include silk on their list of forbidden items. However, this doesn’t take into account the fact that the worms would be extinct if not for the humans who raise them. Regardless of your opinion, it’s an interesting debate, to be sure. As a staunch supporter of lingerie designers who use natural fibers like bamboo, cotton and silk in their designs, you know which side I’m on. Nylon, polyester, lycra and spandex are all petroleum-based materials and I’m sure we can all agree that we need to decrease our dependence on oil, no matter what you think of the snafu in Iraq.

Share This Post

Leave a reply