ABOUT SILK: 

SILK is a fibre produced as a cocoon covering by the silkworm, and valuable for its use in fine fabrics and textiles. The silkworm, in fact, is not a worm but a caterpillar. Although cocoon coverings of fibre are made by a large number of insects, only those of the mulberry silk moth, Bombyx mori, and a few other moths closely akin to it, are used by the silk industry. The silk of other insects is generally used for certain manufacturing purposes, particularly for the cross hairs of telescopes and other optical instruments. 

ORIGIN OF SILK Silk is one of the oldest known textile fibres and, according to Chinese tradition, was used as long ago as the 27th century BC. The silkworm moth was originally a native of China , and for about 30 centuries the gathering and weaving of silk was a secret process, known only to the Chinese. Legend has it that Lady Hsi-ling-shi, the 14-year-old bride of the Emperor Huang Ti, discovered the invention of the first silk reel.

The key to understanding the great mystery and magic of silk, and China's domination of its production and promotion, lies with one species: the blind, flightless moth, Bombyx mori. It lays 500 or more eggs in four to six days and dies soon after. Each egg about the size of a pinhead - one hundred of them weigh only one gram. The female dies almost immediately after depositing the eggs and the male lives only a short time after. From one ounce of eggs come about 30,000 worms which eat a ton of mulberry leaves and produce twelve pounds of raw silk. The original wild ancestor of this cultivated species is believed to be Bombyx mandarina Moore, a silk moth living on the white mulberry tree and unique to China. The silkworm of this particular moth produces a thread whose filament is smoother, finer and rounder than that of other silk moths. Over thousands of years, during which the Chinese practiced sericulture utilizing all the different types of silk moths known to them, Bombyx mori evolved into the specialized silk producer it is today; a moth which has lost its power to fly, only capable of mating and producing eggs for the next generation of silk producers.

Sericulture, the cultivation of the silkworm, spread through China making silk a highly valued commodity much sought after by other countries. In 139 BC the world's longest trade route was opened stretching from Eastern China to the Mediterranean Sea. It was named the Silk Road after its most valuable commodity. China successfully guarded the secret until 300 AD, when Japan, and later India, penetrated the secrecy.

References in the Old Testament indicate that silk was known in biblical times in western Asia, from which it was presumably transplanted to the Greek Islands of the Aegean Sea. The Chinese are believed to have built up a lucrative trade with the West from the days of the Han dynasty in the 2nd century BC. The ancient Persian courts used Chinese silks, unravelled and rewoven into Persian designs. When Darius III, king of Persia, surrendered to Alexander the Great, he was clothed in such silken splendour that Alexander was completely overshadowed and demanded as spoils the equivalent of $7 million in silk. Caravans carried silk on camelback from the heart of Asia to Damascus, Syria, the marketplace at which East and West met. Here silk was traded for Western luxuries. Silk became a valuable commodity in both Greece and Rome. The Roman statesman and general Gaius Julius Caesar restricted silk to his exclusive use and to use for the purple Roman stripes on the togas of officials he favoured. Despite this, however, the use of silk in Rome spread in the era of pomp and display.

Until AD550 all silk woven in Europe was derived from Asiatic sources. About that time, however, the Roman emperor Justinian I sent two Nestorian monks to China, where, at the risk of their lives, they stole mulberry seeds and silkworm eggs, hid them in their bamboo staves, and brought them to Byzantium. Thus, the Chinese and Persian silk monopolies ended. With the spread of Islam, the silkworm came to Sicily and Spain. By the 12th and 13th centuries Italy had become the silk centre of the West, but by the 17th century France was challenging Italy's leadership, and the silk looms established in the Lyons area at that time are still famous today for the unique beauty of their weaving.

Not until after the revocation of the Edict of Nantes did Huguenot weavers from France cross the English Channel and establish silk mills in Spitalfields, a district in the East End of London. The silkworm, however, did not flourish in the English climate, nor has it ever flourished in the United States. The first silk mill in the U.S. was erected in 1810. With the advent of the power loom and with the help of the high tariffs, introduced during the American Civil War, against imported woven goods, the American silk-weaving industry entered a period of growth. However, only in China, Japan, and, to a lesser extent, Italy and France was the silk itself produced.

In addition to the true silk from the cultivated mulberry silkworm, a number of so-called wild silks are produced from other related species of insects in the uncultivated state. Tussah silk, for example, is produced from a species that feeds on oak leaves. Douppioni is a silk produced from two silkworms that spin a cocoon together and thus produce a double thread. Special types of weaves, such as shantung and other irregular types, are woven from these types of silk.

THE SECRET OF SERICULTURE    Producing silk is a lengthy process and demands constant close attention. To produce high quality silk, there are two conditions which need to be fulfilled – preventing the moth from hatching out and perfecting the diet on which the silkworms should feed. Chinese developed secret ways for both.

* The eggs must be kept at 65 F degrees, increasing gradually to 77 degrees at which point they hatch. After the eggs hatch, the baby worms feed day and night every half hour on fresh, hand-picked and chopped mulberry leaves until they are very fat. Also a fixed temperature has to be maintained throughout. Thousands of feeding worms are kept on trays that are stacked one on top of another. A roomful of munching worms sounds like heavy rain falling on the roof. The newly hatched silkworm multiplies its weight 10,000 times within a month, changing colour and shedding its whitish-gray skin several times.

*The silkworms feed until they have stored up enough energy to enter the cocoon stage. While they are growing they have to be protected from loud noises, drafts, strong smells such as those of fish and meat and even the odour of sweat. When it is time to build their cocoons, the worms produce a jelly-like substance in their silk glands, which hardens when it comes into contact with air. Silkworms spend three or four days spinning a cocoon around them until they look like puffy, white balls.

*After eight or nine days in a warm, dry place the cocoons are ready to be unwound. First they are steamed, boiled or baked to kill the worms e.g. immersion in boiling water, steaming or drying in an oven.  The cocoons are then dipped into hot water to loosen the tightly woven filaments. These filaments are unwound onto a spool. Each cocoon is made up of a filament between 600 and 900 meters long! The amount of usable silk in each cocoon is small; about 30,000 worms are required to produce twelve pounds of raw silk. Between five and eight of these super-fine filaments are twisted together to make one thread.  So it takes hundreds of silkworms to produce just one silk scarf or tie.

*Finally the silk threads are woven into cloth or used for embroidery work. Clothes made from silk are not only beautiful and lightweight, they are also warm in cool weather and cool in hot weather. 

Reeling silk and spinning were always considered household duties for women, while weaving and embroidery were carried out in workshops as well as the home. In every silk-producing province the daughters, mothers and grandmothers of every family devoted a large part of the day for six months in a year to the feeding, tending and supervision of silkworms and to the unravelling, spinning, weaving, dyeing and embroidering of silk. By the fifth century BC, at least six Chinese provinces were producing silk. Each spring, the Empress herself inaugurated the silk-raising season, for silk production was the work of women all over China. The technique and process of sericulture were guarded secrets and closely controlled by Chinese authorities. Anyone who revealed the secrets or smuggled the silkworm eggs or cocoons outside of China would be punished by death. 

SILK AND ITS TRADE   Silk became a precious commodity highly sought by other countries at a very early time, and it is believed that the silk trade was actually started before the Silk Road  was officially opened in the second century BC. An Egyptian female mummy with silk has been discovered in the village of Deir el Medina near Thebes and the Valley of the Kings, dated 1070 BC, which is probably the earliest evidence of the silk trade. During the second century BC, the Chinese emperor, Han Wu Di's ambassadors travelled as far west as Persia and Mesopotamia, bearing gifts including silks. A Han embassy reached Baghdad in AD 97, and important finds of Han silks have been made along the Silk Road. One of the most dramatic finds of Tang silks along the Silk Road was made in 1907 by Aurel Stein. Some time around 1015, Buddhist monks, possibly alarmed by the threat of invasion by a Tibetan people, the Tanguts, sealed more than ten thousand manuscripts and silk paintings, silk banners, and textiles into a room at the Caves of the Thousand Buddhas near Dunhuang, a station on the Silk Road in north-west Gansu .

From about the fourth century BC, the Greeks and Romans began talking of Seres, the Kingdom of Silk. Some historians believe the first Romans to set eyes upon the fabulous fabric were the legions of Marcus Licinius Crassus, Governor of Syria. At the fateful battle of Carrhae near the Euphrates River in 53 BC, the soldiers were so startled by the bright silken banners of the Parthian troops that they fled in panic. Within decades Chinese silks became widely worn by the rich and noble families of Rome. The Roman Emperor Heliogabalus (AD 218 - 222) wore nothing but silk. By 380 AD, Marcellinus Ammianus reported, "The use of silk which was once confined to the nobility has now spread to all classes without distinction, even to the lowest." The craving of silk continued to increase over the centuries. The price of silk was very high in Rome. The best Chinese bark (a particular kind of silk) cost as much as 300 denarii (a Roman soldier's salary for an entire year!). Many sources quote that Roman citizens' demand for imported silks was so great as to be damaging to the Roman economy.  Silk was even beginning to have a civilizing effect on the barbarians. In 408 AD when Alaric, a Goth, besieged Rome, his price for sparing the city included 5000 pounds of gold, 3000 pounds of pepper, 30,000 pounds of silver and 4000 tunics of silk.

SILK DEVELOPMENT IN CHINA   When silk was first discovered, it was reserved exclusively for the use of the ruler. It was permitted only to the emperor, his close relations and the very highest of his dignitaries. Within the palace, the emperor is believed to have worn a robe of white silk; outside, he, his principal wife, and the heir to the throne wore yellow, the colour of the earth.

Gradually the various classes of society began wearing tunics of silk, and silk came into more general use. As well as being used for clothing and decoration, silk was quite quickly put to industrial use by the Chinese. This was something which happened in the West only in modern times. Silk, indeed, rapidly became one of the principal elements of the Chinese economy. Silk was used for musical instruments, fishing-lines, bowstrings, bonds of all kinds, and even rag paper, the word's first luxury paper. Eventually even the common people were able to wear garments of silk.

During the Han Dynasty , silk ceased to be a mere industrial material and became an absolute value in itself. Farmers paid their taxes in grain and silk. Silk began to be used for paying civil servants and rewarding subjects for outstanding services. Values were calculated in lengths of silk as they had been calculated in pounds of gold. Before long it was to become a currency used in trade with foreign countries. This use of silk continued during the Tang as well. It is possible that this added importance was the result of a major increase in production. It found its way so thoroughly into the Chinese language that 230 of the 5,000 most common characters of the mandarin "alphabet" have silk as their "key".

SILK TODAY   World silk production has approximately doubled during the last 30 years in spite of man-made fibres replacing silk for some uses. China and Japan during this period have been the two main producers, together manufacturing more than 50% of the world production each year. During the late 1970's China, the country that first developed sericulture thousands years ago dramatically increased its silk production and has again become the world's leading producer of silk.

TYPES OF SILK   Four different types of silk thread may be produced from the procedure called throwing (the raw silk is twisted into a strand sufficiently strong for weaving or knitting): crepe, tram, thrown singles and organzine. Crepe is made by twisting individual threads of raw silk, doubling two or more of these together, and then twisting them again. Tram is made by twisting two or more threads in only one direction. Thrown singles are individual threads that are twisted in only one direction. Organzine is a thread made by giving the raw silk a preliminary twist in one direction and then twisting two of these threads together in the opposite direction. In general, organzine thread is used for the warp threads of materials, tram threads for the weft or filling, crepe thread for weaving crinkly fabrics and a single thread for sheer fabrics.