This section is from the book "Text-Book On Domestic Art", by Carrie Crane Ingalls. Also available from Amazon: Textbook On Domestic Art: With Illustrations And Drafts.
Silk, the most perfect of all fibers, is obtained from the cocoon of the silkworm and has few, if any, impurities. It is divided into two classes, the cultivated and the wild, the latter being found principally in Southern Asia while the cultivation of the former (also produced there) is one of the chief industries of Southern Europe. The finest quality comes from the worm fed on the mulberry tree. The silk fiber is spun from the head of the caterpillar in one long continuous strand often measuring over a thousand yards which is thrown irregularly back and forth while forming the cocoon, being thickest on the outside, where the spinning or weaving commences.
After the cocoons are spun, the pupae (or chrysalis, which emits as the moth) are generally killed by means of steaming, after which the cocoons are sorted according to quality, the best being used to produce warp threads, the purer grades (called tram) for the woof. After drying, the long fiber is reeled off, when it is known as the "raw silk" of commerce.
This raw silk is woven into fabrics or twisted and doubled with other silk fibers for embroidery silks.
There are many varieties depending on food, cultivation or country; the wild containing the impurities, which in the process of dyeing, especially black, renders the fabric stiff.
More than two thousand years B. C, the Chinese wrought beautiful fabrics of this wonderful fiber, which has ever since proved to be the choicest of all textiles.