Photos by Karen Selk
DISCOVERY AND SECRECY SURROUNDING SILK
More than 4500 years ago, a Chinese empress discovered how to unravel silk cocoons when one dropped into her cup of tea. Until this time, fibre for cloth came from plants (cotton, linen, hemp, ramie) or animals (sheep, goats, camel and yak). No one knew of such a fine and shiny fibre as silk, and no one would have believed it came from the secretions of an insect. As the Chinese and other nations began to travel around the world, they each sent ambassadors bearing gifts to other countries. Silk was the most treasured gift from China, and her intelligent emperors soon realised they had a very important trade commodity. To meet the great demand for silk, the emperors ordered their citizens to pay a portion of their taxes in silk cloth. And to help insure that they would remain an important trading power, the government imposed a law that anyone who revealed the secret of silk production would be put to death.
The mystery of how silk was produced was not revealed to the western world for over 3000 years. One tale is told of two Christian monks who were sent to China to discover the age-old secret of silk production. They returned to Constantinople two years later with silkworm eggs and mulberry tree seeds hidden in hollowed out canes. From here, silk production spread throughout Europe.
SERICULTURE
Raising silkworms is called sericulture and is an agricultural-based livelihood that depends heavily on the weather and the attentiveness of the farmer. It is practised throughout Asia, Russia, Turkey and Brazil with China being the largest producer. Workers feed the hungry silkworms fresh, chopped mulberry leaves eight times a day. The silkworms are moved to clean feeding trays once a day.
Some years the silk quality is high, while other years the farmers suffer financially because of poor crops. The price of silk fluctuates with market supply and demand. The economic status of silk-rearing countries also plays an important role in the price of silk. As those countries become more affluent, like Japan, more farmers leave the agriculture industry in search of higher paying jobs. As fewer farmers are willing to carry on the labour-intensive work of raising silkworms, silk is becoming more scarce and costly.
SILKWORM
The scientific name for the silkworm is Bombyx mori. The silkworm is not a worm at all, but a caterpillar that transforms into a moth. It starts its life in spring as an egg the size of a sesame seed. A silkworm increases its body weight 10,000 times during its life of 28-30 days. If a human baby grew that fast, in two months it would weigh as much as an adult elephant.
LOUIS PASTEUR SAVES SILK INDUSTRY
Disease
and infection can spread rapidly through a silkworm colony.
To combat this problem, each female is placed in a numbered
space to lay her eggs and is examined microscopically to ensure
there is no disease. If there is any sign of contamination,
all the eggs from that female are destroyed. Disease wiped out
the European sericulture industry in the mid 1800s. Eventually
Louis Pasteur found the source of the disease by testing female
moths after they laid their eggs.
THE COCOON
When the silkworm is ready to make the cocoon, it is given a small nook of twigs, braided straw or bamboo. They spin two semi-liquid proteins together at a rate of 30cm (1 foot) per minute while turning 200,000 times in the three days it takes to form a cocoon. It makes a strand of silk as long as 12 football fields which solidifies and becomes a thread when it meets the air outside the silkworm's body.
METAMORPHOSIS
TO MOTH
Inside its cocoon, the silkworm goes into a deep sleep for 11-12 days, while its body goes through a change, or metamorphosis, from silkworm to moth. When this pupa becomes a fully grown moth, it excretes a brown enzyme dissolving a hole in the cocoon. The flightless moth wiggles out and begins searching for a mate. The female moth produces a special scent called a phermone to attract the male moth. One or two days after the male fertilises the eggs inside the female's body she lays 300-500 eggs.
UNRAVELLING THE COCOON INTO SILK YARN
The silken strand from one cocoon is too fine to make into cloth, so 6-20 cocoons are reeled, or unravelled, at the same time. The sericin sticks the strands together to make a thread the size of a human hair. A strand of silk is stronger than a similar-sized filament of steel, yet very lightweight. The left over pupae are rich in protein. They are used as fish food, pressed into oil and people in some countries eat them.
HOW MANY SILKWORMS DOES IT TAKE
One silk shirt uses cocoons from 1,000 silkworms, which eat 22 kg (48 lb) of mulberry leaves.
CAPS AND HANKIES
There are approximately 60 cocoons per cap. A bell weighing 1 kg contains 25 caps which contain silk fibre from approximately 1600 cocoons. One person can stretch 5 kg of cocoons into hankies per day. One kilo of cocoons will produce .15 kg of hankies. One person makes .75 kg of hankies per day.
WILD SILKWORMS
There are more than 500 kinds of silk-producing caterpillars. We can harvest silk from only a few, tussah being the most common. The silk made by the rest is not strong enough or is impossible to unravel.
MAKING A SARI OF TUSSAH SILK
To make a sari 44 inches wide and 5 yards long you need: 8,000 silkworm eggs, which will yield 1,200 cocoons (because of high mortality rate). These silkworms will eat the leaves of between 12 and 14 trees, each approximately 12 feet tall. It will take over 112 hours (14 eight hour days) to prepare the 14 ounces of yarn necessary to weave the lightweight sari.
THE SILK ROAD
The Silk Road was established as a trade route in the fifth century BC. Extending 8,000 km (5,000 mi.); it was the longest road on earth. Goods were transported from Byzantium (Istanbul), the eastern capital of the Roman Empire, across the Middle East and Central Asia to Xian, the capital of China. Camel caravans from the east carried gems and spices from India, furs from Siberia, silk, porcelain and paper from China. From the west came perfumes and cosmetics from Egypt and Arabia, ivory from Africa, horses from Central Asia, and gold, silver and glass from Constantinople and Rome.
The Silk Road was never really a single road, but rather a shifting network of desert tracks and mountainous trails. The trek across the route was a series of journeys from trading centre to trading centre where merchants traded and sold goods to other dealers who then carried them further along the route. The slow journey was extremely hard, and merchants endured tremendous risks to life and capital, including the threat of roving bandits.
The Silk Road began as an avenue for commerce, but became an equally important means for isolated societies to exchange ideas, philosophies, artistic styles and to learn about the outside world.
SILK TRAINS RACE ACROSS NORTH AMERICA
Just as the Silk Road carried silk from Asia to Europe, the Silk Trains carried silk from the western parts of North America, across the Rockies and plains, to the silk mills of Montreal, New York and New Jersey. The late 1880s saw ships arriving from China and Japan in the ports of Seattle, Vancouver and San Francisco. They carried millions of dollars worth of raw silk destined for spinning mills in the east. The insurance on the valuable silk in transit was paid on an hourly basis, at 6% of the value of the shipment.
The Silks, as the silk trains were dubbed, had the right of way over all other traffic. This accounted for a 24-hour difference in trans-continental travel time between the silk and passenger trains. The cars of the silk trains were specially lined with finished steel or varnished wood to minimise the damage to the delicate silk fibres during the abrasive journey. An average train of 7-13 cars, each carrying 35 tons of silk worth approximately $350,000, travelled the distance in an unprecedented 90 hours. To appreciate the value of that cargo in 1919, compare the cost at that time of a new Model T car at $560 and a chocolate dipped, double scoop ice cream cone at $0.05.
The excitement and hustle on the docks had to match what was happening on the rails. It took an average of 1 hour and 40 minutes to unload a ship of 280 tons of cargo, load an eight-car train, and brace the silk bales to minimise shifting during transit.
The stock market crash of 1929 was the beginning of the decline of the Silks. The depression that followed decimated the market for luxury silks. In addition to the sharp decline in the value by silk, Japan built its own fleet of the fast ships to transport its silk to New York via the Panama Canal.
Bell:
A unit of silk caps weighing one kilo. The bell contains silk fibre from approximately 1,600 cocoons.
Bombyx
mori:
The Latin name of the silk producing caterpillar that feeds on mulberry (morus alba) leaves. Its cocoon is the source of fine, white silk. It is reared throughout Asia.
Bourette Silk:
Noil is another term used for a by-product fibre and yarn after higher quality reeled and spun silk are removed from a cocoon.
Caps:
After cocoons have been partially degummed, the fibres are expanded and stretched over a piece of bamboo, bent into an arch shape. Hand spinners use this sort of fibre to make yarn.
Degumming:
The process of removing natural gum or sericin from silk goods or yarns by boiling in soap solution.
Denier:
A unit of measure by which silk yarn is weighed and its fineness calculated.
Douppion:
Silk formed by two worms united to spin a single cocoon which is therefore composed of two filaments. They may be reeled into a coarse slubby yarn which is used in the manufacture of pongee, shantung, douppion and other textured silks.
Eri (or Endi):
The common name of the Samia ricina caterpillar which eats the leaves of the castor plant (ricinus communis) or kesseru (heteropanax fragrans). This is a semi-domestic silk producing caterpillar reared in Assam, India. The silk is white in colour, with a semi-matt finish.
Filature:
An establishment for the production of raw (reeled) silk from cocoons.
Gum (or sericin):
A protein material that coats the filaments of raw silk as it is extruded from the silkworms body. This gum bonds the filaments of silk together and aids in the formation of the cocoon. During silk manufacture, the gum is useful as a natural sizing in weaving.
Hankie:
After cocoons have been partially degummed, the fibres are expanded and stretched by hand over a frame forming approximate 10" squares. Handspinners use this form of fibre to make yarn.
Muga:
The common name of the Antherea assama caterpillar which eats the leaves of the Som tree (machilus bombycine) or Soalu (litsaea polyantha). This is a wild caterpillar reared in Assam, India. The silk produced is golden in colour.
Mulberry:
Common name of the Morus alba tree, which is the sole food of the Bombyx mori silk producing caterpillar.
Schappe Silk:
This refers to any spun silk yarns (ie: not reeled) which had been degummed by a lengthy and very smelly fermentation process.
Scroop:
The peculiar scrunching or rustling sound silk acquires when treated with certain organic acids (acetic and formic).
Shot Silk:
A fabric woven with different coloured warp and weft thread so as to make a tinted or iridescent appearance.
Tussah (or Tasar, Tussore):
A wild silk of the Antherea mylitta caterpillar which eats the leaves of the Arjun tree (terminalia arjun), Asan (terminalia tomentosa) or Oak (querus). This caterpillar is raised in the forested regions of China, Korea and India. The silk is honey beige colour.
Weighted Silk:
The practice formerly used to compensate for the loss of the sericin weight during silk processing. Usually done with tin salts. This caused the fabric to be brittle and wear badly.