Behind The Fabric: Silk
By Mike-Dave Ayeni
Sustainable Fashion Writer
One of the finest existing fabrics with a long reputation for luxury, silk is the world's strongest natural fibre. Described as the diamond of fabrics by Oscar De La Renta, this lovely, lustrous fabric is the product of a protein known as fibroin, which is synthesised by silkworms (Bombyx Mori) to make their cocoons.
In addition to being beautiful and durable, this super fabric is also highly breathable, with very high wicking abilities, extremely comfortable and absorbent, and has thermostatic abilities with which it is able to keep you warm in cold weather and keep you cool in warm weather.
Amazingly versatile, this fabric is as favoured for use in Haute Couture creation (especially bridal couture) for how well it drapes as in luxury furnishings and upholstery, beddings, curtains, sleepwear and in medicine for its therapeutic healing abilities, a result of its powerful autoimmune properties.
However, the production and use of this wonderful fabric have quite a few adverse impacts on the environment, and it is important that these effects are taken into consideration in our patronage of sericulture. But first let us explore the millennia-long journey of silk, silk production and silk trade.
The History of Silk
Sericulture, the production and processing of silk, has been found to have originated from Asia, specifically China. Archaeological data suggests that the existence of silk in the Chinese civilisation dated as far back as eight and a half millennia ago (6500 BC), and there is irrefutable proof that China used silk as long ago as 3600 BC.
Legend has it that sericulture had been discovered and invented by a Chinese Empress, Xi Ling Shi, who was married to the mythical Yellow Emperor Leizu. The Empress had been resting, having her afternoon tea under a mulberry tree when a cocoon fell out of the tree and into her tea. As the heat of the tea dissolved the gum that held the cocoon together and the cocoon began to unravel in her cup, the thought occurred to her that these shimmery strands of fibre could be woven into a fine fabric and thus, sericulture was born.
The art became a closely guarded secret amongst Chinese nobility as the fame and demand for the fabric grew, to the point where it was considered a crime against the state to share secrets of silk production, one punishable by death. As the Chinese economy improved, however, even commoners gained access to silk, and eventually, another legend tells that the secrets of silk production got leaked outside the kingdom by a Chinese princess who was to be married to a foreign nobleman. She hid cocoons of mulberry silkworms in her elaborate hairdo and presented them to her new kingdom on arrival.
The trade of silk was such a booming and lucrative one that it built a major trade route and the Silk Road is still known by that name to date. The silk road was established upon the institution of silk production in other parts of Asia like Thailand, India, and Korea and although the silk produced in China was still considerably dominating the market, it facilitated the trade of silk from Asia to as far as Western Europe.
While there exist historical records that seem to point to the fact that silk had also been produced in the west as well, none have been proven.
Throughout those times and into the middle ages, silk gained more prominence, spreading in the West, in Italy and America until the development of synthetic fabric options in America after the second world war.
How Silk Is Made
The silk production process has not greatly evolved since pre-industrial times, and that is where a lot of our concerns lie.
Domesticated mulberry silkworms are bred in captivity for silk production and usually, after this, the male adults are usually disposed of. The female adult moths breed from three hundred to five hundred eggs upon mating, after which the females are crushed for their eggs, and if they are discovered to be diseased after this, those eggs are also destroyed to prevent the spread of disease.
The eggs found to be free of disease are then harvested and incubated up until the larva stage. At this stage, they are fed an exclusive diet of mulberry leaves and in six short weeks, begin to get to spinning their cocoons. A hundred meters of fibre is spun in about 6-8 days and this is done by spinning their bodies around and around, a silkworm can undergo up to three hundred thousand rotations at this stage to create the cocoons.
In the breeding of silkworms, most are not permitted to live long enough to reach maturity and those that are left alive become breeders. This is because once the silkworm builds its cocoon, all set to pupate, the cocoons are harvested and boiled to break down the compound that holds them together, killing the silkworm in the process. An estimated one thousand silkworms give their lives to produce just one silk shirt, and about two thousand five hundred silkworms die to give us one pound of raw, unprocessed silk.
After boiling, each cocoon is slowly unravelled one by one to give one fine long continuous thread. Each thread is carefully wound onto a reel, washed to remove all the residual gum, properly bleached, dried and then soaked in dye to pigment each thread. Once dyed, they are unravelled from the reel and spun onto a bobbin to begin the process of weaving them into the fabric.
Depending on the pattern used in weaving, silk can be produced into fabrics of different thicknesses and textures, and on weaving can be printed on into various patterns for varying effects.
The final stage is where silk is treated, usually using harsh chemicals to give it different types of effects like crease and fire-proofing. From here on the finished silk fabric can be made into pretty much any kind of fashion product.
Is Silk Eco-friendly?
Arguments can be made both ways when it comes to this fabric, in that first, it is 100% natural, and so is also a hundred per cent biodegradable in its untreated state. Also, the fabric does not shed, and will not co tribute to microplastic pollution. In addition, the mulberry trees used in silk cultivation have fewer chemical requirements for their growth than other plants.
However, the chemicals used in silk production, like dyes, for example, would adversely affect its ability to biodegrade. Also, silk cultivation requires a lot of mulberry trees, and this means chemicals like fertilisers and pesticides will be used to facilitate their growth. These chemicals contribute to groundwater and water body pollution and can result in an algae bloom, leading to eutrophication.
Silk production also requires a lot of water at various stages. Water is used in boiling the cocoons, in the bleaching and dyeing processes, and in cleaning at various stages. Not to mention the amount of energy consumed in incubating, boiling and treating the fabric.
To add to the pollution concerns, the chemicals used in the dyeing and treatment of silk tend not to be properly treated before disposing of, and they are often discharged into water bodies.
Is Silk Ethically Produced?
Beginning with the harvesting process that results in the death of thousands of silkworms, it is difficult to argue for the ethicality of silk production. There is also the fact that child labour is a prevalent practice in silk production. Little children aged 5-12 are exposed to unhealthy unsafe and toxic conditions that are not even safe enough for adult workers. Silk production mostly takes place in countries with the most exploitable workers. Toxic fumes, boiling water and sometimes carcinogenic chemicals— the silk production process is in need of a lot of revision.
What Alternatives Are There?
Silk production in the traditional sense leaves a lot to be desired in ethical and sustainable practices. Thankfully better ways have been found to produce silk with less harm:
- Peace Silk is produced by harvesting the cocoons after the moths have emerged from them.
- Wild Silk is produced from the cocoons of silkworms found in the wild. These worms have a wider diet range than domesticated worms and so produce a stronger though less consistent fibre.
- GOTS-certified organic silk is produced with zero harmful chemicals and allows for more diet range. Same with Oeko-tex certified silk, which makes it a more sustainable practice, except for the fact that the silkworms still get boiled alive.
- Recycled silk is made using preexisting silk fabric and it eliminates the harmful processes used in virgin silk production.
- Vegan silk is produced using plant alternatives, like cactus fibres, pineapple and banana fibres and lotus silk.
While silk is an amazing, highly sought after fabric, it leaves so much to be desired in its conventional production process. Thankfully, there are more than a few alternatives created towards increasing the sustainable and ethical production of silk, but even with these efforts more can be done to improve the quality of production that goes into creating silk.