Vivienne McInnis, age 11, of Toronto, Ontario, Canada, for her question:
How do they make real silk?
Throughout human history, the richest fabrics were woven from real silk. Nowadays, we weave silky materials from nylon and other synthetic threads. They are much cheaper because they are man made from plentiful chemicals, such as the simple hydrocarbons in petroleum. But they do not have the lustrous texture of real silk. As always, this loveliest of fabrics is rare and costly.
Threads of real silk are not made by human hands. They are spun by several members of the insect world, though the best ones are created by the larvae of the silkworm moth. This hungry caterpillar has been pampered for ages and is very, very fussy. His food and his surroundings must be just so, or he pouts and sinks into a decline. This ends his usefulness because he does not spin his fine silk unless he finishes the caterpillar phase of his life in good condition.
Most silkworm farmers live in Japan and other places where certain mulberry trees grow in abundance. Usually the operation is run by a family and during the busy season nobody has a moment to spare. The operation may begin with just one ounce of pale little silkworm eggs. For six weeks or so, the eggs must be kept in a warm well¬ventilated room and no loud noises. When at last they hatch, the tiny silkworms are famished. They are placed on trays arranged on shelves around a warm room. The trays are lined with wire netting and sheets of clean paper. Drafts and dirt may be fatal.
The ounce of eggs yields about 40,000 little silkworms expecting a banquet. The only thing they will eat is mulberry leaves and they must be served freshly picked from the tree. At first the food is minced and shredded. In about five days, they grow too big for their skins. Their human nursemaids worry and pamper them while they molt. With bigger bodies and larger skins, they are ready to eat solid food, which must be whole mulberry leaves, served very dry and slightly wilted.
In the next few weeks, the pampered silkworms devour about a ton of mulberry leaves and molt their skins four more times. The job of feeding and tending them is never done. The trays must be cleaned after every meal and after the last molt they eat twice their weight in food every day.
At last the caterpillar stage of their lives is finished. Dry twigs are placed over the trays and the weary silkworms climb up there to spin their cocoons. Each winds half a mile of silken thread around and around himself. Then he goes into his sleeping pupa stage. Altogether, those hungry silkworms produce about 12 pounds of raw silk.
The cocoons are baked to destroy the living insects inside. Then the silken threads are unwound. The fine strands are woven together to make thicker threads. Most of these are dyed with rich colors before they are woven into lustrous fabrics of pure silk. The luxury material is so costly because of all the work it took to coax those fussy silkworms to spin just a few pounds of silk.