Silk is the most prestigious and luxurious fabric in the world and has been for centuries. It is soft to the touch, glistens naturally, and drapes beautifully. Many people mistakenly think it is a delicate fabric and are scared to wear it let alone sew with it.  Some people even embrace synthetic fabrics that attempt to mimic silk’s fine qualities, but these fabrics are noticeably inferior to silk. It’s long history, potential for environmental sustainability, and unique qualities are the reason silk will remain a premier fiber in the textile world.

History of Silk

The earliest authentic references to silk date back to China in 2200 B.C. where it was chronicled in ceremonies as a gift paying homage to emperors. Although, it is believed silk is even older. Legend has it that a Chinese Empress (2600 B.C.) discovered it when a cocoon fell from a mulberry tree into her tea, and the cocoon dissolved into long silk threads. Needless to say the production of silk (sericulture) has been around for a long time.

Sericulture was a closely guarded secret in China for many centuries, but the secret eventually made its way to Korea by 1200 B.C. and India by 140 B.C. Silken goods from China were a major trade staple to Persia and later Rome, hence, the trade route became known as the Silk Road, a route that was over 8,000 kilometers by sea and land. Sericulture made its way to Constantinople around 560 A.D. and later spread to Europe.

Sericulture was especially prominent in areas of present day Italy and France, and they provided most of the silk to Europe from the 10th to the 19th century. However, in the 19th century a disease nearly wiped out the silkworm in France, but, thanks to Louis Pasteur it survived. He identified that temperature, humidity, ventilation, quality of food, sanitation and adequate separation of the broods of newly hatched worms played a role in susceptibility to the disease. Not only did Pasteur’s research save the silkworm but the concept of an environment’s influence on a contagion was an important scientific discovery.

The silkworm plague in Europe combined with the opening of the Suez canal (1869) caused Europe to lose its dominance in the silk market. Asia became the world leader with Japan leading. Japan learned of sericulture when it invaded and occupied Korea in the early 20th century, and was a key player in scientific research and the modernization of silk production. Before World War II, Japan controlled 60 percent of the world’s production of silk and remained the leader until the 1970’s.

However, the development of silk substitutes (nylon) and synthetic fabrics (polyester) during and after the war led to a sharp decline in global silk production. Today, silk only accounts for 0.2 percent of all total global textile production. In 2017, approximately 178,000 metric tons of silk were produced, with China being the number one producer (142,000 tons), and India the second largest producer (32,000 tons). The United States is the largest consumer of silk. Silk has played a significant role in political and global trade relationships for centuries and continues to effect the global economy today.

Sericulture

Silk is made from the cocoon of the domesticated Bombyx Mori caterpillar also known as the mulberry silkworm.  There are many animals that create silk (e.g. spiders, mussels, wasps) and other types of silkworms (e.g. Eri, Tussah, Muga) from which silk is harvested, but the mulberry silkworm is the most common, and provides 90 percent of the silk in the world.

The production of silk begins with the hatching of tiny caterpillars from eggs (seeds).

The caterpillars (larva stage) are fed leaves from the mulberry tree until they grow into large caterpillars.

The large caterpillars then spin a cocoon (pupa stage).

After this stage is complete, the cocoon is exposed to steam, hot water, or warm air in order to harvest the silk, which of course kills the pupa. If the moth emerged from the cocoon it would break the valuable silk thread. The cocoon is made of a long single thread of raw silk that is 300-900 meters long. The ideal silk is reeled from these long continuous threads. It takes about 12 pounds of cocoons (3000 cocoons) to make a pound of raw silk. Because the mulberry silkworms have been selectively bred to maximize output, they cannot exist without human assistance. The moths that are allowed to emerge mate immediately, and the female lays about 300-500 eggs. These eggs are then refrigerated so that the process can begin again. The adult moths only live about 4-5 days, but this is the case with most short-lived moth species. They have brief lives because they have no way to ingest food and just live on stored nutrients. As adults, reproduction is their only function in life.

The threads obtained from the cocoons are either sold as yarns or woven into fabric, and may be further processed with dying and finishing treatments.

There has been a movement towards “Ahimsa silk”, “peace silk”, and “wild silk” whereby the moth is allowed to emerge from the cocoon. Ahimsa is an Eastern philosophy of “not to hurt any living thing”. Since the silk threads are broken and soiled upon the emergence of the moth, the threads must usually be spun (like cotton) versus reeled. Spun silk is considered a lesser quality than reeled silk because of its reduced strength and luster. There is still plenty of human interference in the production of peace and wild silks as is with the traditional method, and all the moths do not necessarily fly away and live long lives. There are environmental benefits to this method. Many peace sericulturists may use organic farming methods and more benign dyeing and finishing treatments to the silk than the other highly industrialized method. Peace sericulture tends to be done on a smaller scale, which is generally economically viable and beneficial to the rural communities producing it.

The merits of silk

Silk has many great qualities. The prism-like triangular structure of the silk fibers gives silk its natural shimmering look. It is strong yet lightweight. It actually has a tensile strength comparable to steel. It is highly absorbent and can hold upwards of 30 percent of its weight in moisture, but it also dries quickly, which makes it ideal for regulating body temperature. It is easy to clean and accepts dyes well.

Silk is also a good choice in terms of its environmental and social impact. It is agro-based but it relies mostly on manual labor and not large farming equipment for its cultivation. It is beneficial to rural economies where food-crop cultivation is not viable. Families in rural areas can earn a greater income because of the low investment costs and high yield of sericulture. Silk does not rely on petroleum and dangerous chemical compounds as many synthetic fabrics do, nor does it require as much water to produce as cotton. There also tends to be a high rate of women in the silk production workforce, which promotes greater gender equality.

As a seamstress and consumer of silk fabric and clothing, I have experienced first hand silk’s superiority to other textiles. It is not difficult to sew as some may fear, and it is extremely resilient. Other fabrics cannot compare to it’s beauty, fluidity and feel. And after 5000 years, it still remains one of the most fashionable and sustainable fibers in the clothing industry.

For further discussion on how to sew with silk, please enter your email address to subscribe to my Newsletter. I will also be teaching on October 13, 2018 from 10:30-1:30 “Sewing with Silk and on the Bias” at Textile Fabrics, 471 Craighead Street, Nashville, TN 37204. For more information email Followthethreadnashville@gmail.com.  I look forward to sewing with you!