From Silkworm to Kimono

By “Awake!” correspondent in Japan

PAMPER a worm and what happens? That depends on the kind of worm. If it is a silkworm, it will require first-class treatment from the day it is born. But the results make it well worth the effort.

A silkworm is the middle, or caterpillar, stage of development for a moth called Bombyx mori. Its life begins when a mature moth lays 300 to 500 eggs. These will develop no further, however, until the temperature is just right.

In Japan, silk farmers put the eggs into cold storage until the following May. Hatching is then staggered. On three or four occasions during the next five months, the eggs are brought into a room with a temperature of about 18 degrees Celsius (65 Fahrenheit). Thereafter the temperature is gradually increased a little each day until it reaches 25 degrees Celsius (77 Fahrenheit). At this point the silkworm makes its appearance.

Weeks of Banqueting

Workers now transport the newborn silkworms to a special feeding room. Here a number of trays, each containing many silkworms, fit one above the other into racks, with about two feet (.6 meter) in between. An attendant places a layer of clean gauze or rush netting across the tray and twice each day spreads mulberry leaves on it. Sensing this, the silkworms wiggle and push their way through the covering and begin eating ravenously.

This feast lasts for about twenty days. And what a transformation takes place! At birth, the babies are a mere one twelfth of an inch (2.1 millimeters) long. But after weeks of banqueting, they attain a length of up to three and a half inches (89 millimeters), having consumed more than twenty times their own weight. The body of a fully grown silkworm may be nearly an inch (25.4 millimeters) thick, and is filled with liquid silk.

Having finished gorging themselves, the silkworms lift the forepart of their bodies into the air and begin waving them to and fro. When they do this, workers recognize that it is time for the worms to begin spinning their silken cocoon.

Palace of Silk

For this activity, carpenters have built special frames with cubbyholes two and a half inches (63 millimeters) long by two inches (51 millimeters) high, which are open on both ends. One silkworm goes into each of these compartments.

Settled within its own cubbyhole, this unique caterpillar begins to spin a palace of silk. “To do this,” notes The World Book Encyclopedia, “it swings its head from side to side in a series of figure-eight movements. Two glands near the silkworm’s lower jaw give off a fluid that hardens into fine silk threads as it hits the air. At the same time, it gives off a gum called sericin. The sericin firmly cements the two threads of silk together.” This continues for about three days, until all the liquid silk is used up. A completed cocoon will involve a strand of silk thread some 1,300 meters (4,265 feet) long.

Inside the finished cocoon the caterpillar changes into a pupa. This begins the third, or moth, stage of existence for Bombyx mori. If left alone, the pupa will grow into a moth and force its way out of the cocoon, breaking the silk thread in hundreds of places. To prevent this, the cocoons are passed through hot-air pipes, killing the developing moths inside.

Unrolling the Silk

Next, workers gather the cocoons for boiling. This process softens the sericin gum, making it easy for the end of the silk thread to be caught. Each strand is as fine as a cobweb, and cannot be used individually. Hence, depending on the desired thickness, threads of from four to twenty cocoons will be reeled into a single strand of yarn.

Later, the silk is removed from the reels and twisted into small coiled bundles called “skeins.” Now it is ready for “throwing.” In explanation of this term, The World Book Encyclopedia states: “The term comes from the Anglo-Saxon word thraw (twist). Throwing is increasing the twist or adding strands and twisting them together. The number of threads thrown together. depends on the fabric to be woven.” After throwing, the threads are wound onto bobbins, cones or tubes, which are used in weaving. It is important to do this carefully. A smooth, knotless thread makes the weaver happy.

Weaving and Dyeing

The first step in weaving is called “warping.” This is preparation of the yarn that extends lengthwise through a fabric. Warping is an exacting operation, for each thread must be equidistant from those on either side of it. Otherwise, the warp threads will merge into and cross over one another, ‘resulting in an uneven weave.

The weaver works the cross thread alternately over and under the warp threads. On the loom the warp threads are separated into two sets, so that a cross thread passes over one set when drawn across the warp in one direction and under the same set when moved across it in the opposite way. This woven silk is stiff and lusterless. But after carefully controlled scouring, it appears soft and pearly white.

Now it is time to add color. One way is by hand painting. For this process, in Japan, the plain white cloth is first temporarily sewn into a kimono. Then a skilled hand draws a design with a brush dipped in blue flower sap. Next, starch is squeezed out of a paper funnel and applied to the edges of the design. Inside these boundaries colors are painted and allowed to set. Next, a paste of rice, rice bran, salt and lye is spread over the pattern to prevent absorption by it of dye used for background color.

Another method is stencil dyeing. This procedure requires a stencil for each color of the design. After placing the stencils over the silk, the colors are dabbed on by hand.

Regardless of the method used, it is necessary to steam kimonos for more than half an hour to assure that the colors set. A rinse with running water washes out surplus dye. Knowing a woman’s eye for beauty, an embroiderer adds gold and/​or silver yarn to the already elaborate pattern. A final steam press completes the beautiful kimono.

Young Japanese girls like pastel backgrounds with bright patterns. For special occasions, single girls wear bright kimonos with long hanging sleeves. Those worn by married women are somewhat more subdued; and older women, especially in country areas, prefer plain kimonos in gray or brown. Did you know that Japanese men, too, wear kimonos? Generally they choose plain, dark colors.

Throughout thousands of years the pearly luster and natural folds of silk have appealed to man. Moreover, silk is comfortable to wear because it is a protein and allows the body to breathe. It does not easily catch fire. How appreciative we can be for the Creator’s wisdom in providing the amazing silkworm!​—Ps. 104:24.