Southeast Asia's silk: a nature and human marvel August 07 2014
Silk is a by-product of silkworms gorging on the leaves of mulberry trees. They spin cocoons which are then harvested and boiled. The threads for weaving are drawn from the resulting floss. But while sericulture is similar world-wide, there are major regional differences. In Cambodia, "yellow" silkworms evolved to match the tropical climate, while in the more temperate regions of China and Japan, higher-producing "white" silkworms are the insects of choice.
Thin taffetas silk, slightly see-through, is the lightest and most delicate silk. Soft and silky, it is ideal for summer tunics. Thick taffetas silk is the best silk quality with very few irregularities. It is also much appreciated as it is keeps warm in winter and cold in summer.
There are about a million known species of insects, and entomologists estimate that many millions more have not yet been identified, but of all these species, only one has been domesticated by man: Bombyx mori, the silk moth.
After nearly 5,000 years of selective breeding, silk moths have lost the ability to fly and cannot survive without humans. Many of us wouldn't survive without the moths either -- many, many people around the world depend on the silk moth for their livelihood, from peasant farmers who grow the mulberry leaves the silkworms eat, and rural women who rear the moths and produce the precious cocoons, to the fashion boutiques in the World's capitals that sell the luxury silk garments and fabrics.
Annual world production is estimated at about 100,000 tons, more than 600 billion cocoons. A single cocoon contains anything between 0.5 and 1.5 kilometers of thread. By the time a silkworm starts weaving its cocoon it weighs 10,000 times more than when it hatched from its egg as a tiny creature less than two millimeters long, all from eating mulberry leaves. When the worm cocoons have completely developed, they are harvested and boiled. Ten kilograms of cocoons will produce one kilogram of silk.
There are two stages of carding which produce two distinct qualities of thread: fine silk and raw silk. The cocoons are boiled and the fibers are removed (or carded) in two stages. The outer cocoon is fine silk and the inner cocoon is raw silk.
In the process, nothing goes to waste. After the silk is removed from the cocoons, the silkworms are eaten as a nutritious snack, providing much needed protein and fat. Many cultures all over the world have been eating insects for centuries, and while this may be distasteful to many Westerners, many populations enjoy the taste and the health benefits of silkworms.
After carding, the thread is dyed using natural products such as flowers, leaves, and barks. The dyed threads are dried in the sun.
The technology behind the textiles has changedvery little over hundreds of years. The weavers themselves make the looms; rickety wooden frames tangled in webs of silk and cotton.
In addition to being remarkably beautiful, Southeast Asia's silk is sturdy, soft, colorfast, and machine washable using the gentle cycle. It is used in a wide variety of products, from scarves and clothing to household goods and textiles.