Silk is a natural fiber that is created by silk worms (Bombyx mori) when they make cocoons to become moths. It is extremely fine, lustrous and strong, and makes a very soft fabric with the ability to be crisp or very drapey.
Traditional silk is made by breeding the worms and feeding them mulberry leaves, allowing them to build cocoons, then steaming or baking the cocoons with the worms still inside before boiling to soften then carefully unravelling the cocoon into one long fiber. Those fibers are then spun into a silk thread (it takes about ten fibers for one silk thread), which can be woven into a fabric.
It takes about 3000 silkworms and 104kg of mulberry leaves to produce 1kg of silk.
Qualities of Silk
- Silk is very strong but loses strength when wet.
- It is very lustrous due to the prismatic nature of the silk strands.
- Silk is vulnerable to insects, especially if stored without proper cleaning.
- Silk can deteriorate and fade quickly if left in sunlight.
- Silk has poor elasticity, and will not recover easily from being stretched.
- Silk is susceptible to static cling.
- Silk is absorbent, which makes it ideal to wear in warm weather, but also does not conduct heat, making it also a great underlayer for cooler months.
Care for Silk
- Silk will shrink and must be pre-washed before making a garment. If you have purchased a pre-made silk garment, read care instructions carefully. Most directions will recommend dry cleaning only to reduce shrinkage and avoid staining and water spots.
- Silk can be ironed, but must be ironed on low heat only. Many people recommend using a pressing cloth and dampening the silk before ironing it.
- Silk should be stored in a clean and dark spot as it is vulnerable to destruction by insects (especially when stored dirty!) and will fade and deteriorate in the sunlight.
- Silk’s absorbency makes it comfortable to wear and easy to dye in bright lustrous colours.
- It is soft and strong which make it a comfortable and beautiful choice for clothing.
- It is biodegradable and can be composted.
- Silk is inherently environmentally sustainable. The worms feed on mulberry leaves, which is a renewable crop as the trees grow and produce new leaves. The worms reproduce rapidly and are in no danger of going extinct. If woven by hand in traditional methods such as would be done by weavers in small villages, the environmental footprint from energy usage would be almost none. (Of course larger operations must be evaluated separately, as they are likely to use more chemicals and energy).
- Many people feel that silk’s biggest con is that many thousands of silkworms are boiled to death to make one garment.
- There are alternatives such as ‘Peace Silk’ which allows the moth to leave the cocoon alive, but many of these methods are no better as each moths hundreds of progeny would soon starve to death because at the rate they multiply, no silk producer could possibly feed them all.
- Silk can also be found in the wild, but harvesting silk from wild cocoons is time consuming and costly, and the quality of silk is less lustrous, as well as the strands of silk are broken in many places which results in a more nubbly texture of cloth.
- Silk is very labour intensive to feed, collect and harvest. Labour is often done in countries like China, where labour costs are low. There are often no guarantees that silk is coming from a location where employees were treated fairly and paid well.
- Silk can be very expensive, and cost a lot for one garment compared to cheaper fibers like cotton.
- Silk is sometimes difficult to care for. Although it is strong, it is often manufactured into very lightweight fabrics that can wear or tear easily, and is vulnerable to heat, sunlight, insects, and staining.
- Some silks are bleached, dyed, or treated with special finishes that change the texture or weight of the final fabric, or make it stain resistant or wrinkle resistant. These chemicals should be investigated before purchasing as they may be harmful to your body or the planet.
What to Do With Silk
Silk is one of those fibers that can be ideal in some respects and not ideal in others, depending on your beliefs and feelings about the manufacturing process. It’s biodegradability, beauty, and strength make it sought after and valuable.
However, if the thought of the destruction of thousands of silkworms for one skirt bothers you, then it’s best to pursue other alternatives, like Tencel or other eco-friendly rayons which have a lot of the drape and other good features of silk without the moral cost.
If you DO buy silk, ask questions. Where was it made? How was the silk harvested? Were workers treated and paid fairly? Does it have any special finishes or dyes that might impact the environment or be absorbed by your skin?
Characteristics of Silk Fabrics | Properties of Silk Fabrics. Textile Learner.
Wormspit Library – This is a list of silk related texts that are available digitally including some pdf scans of texts.
Central Silk Board of India. Government of India.