Foreword: Are silk worms animals? If you answer “yes,” best skip this blog and avoid silk yarn.
Occasionally I’m asked why I use silk when I’m animal-fiber-free. Call it a result of mountain living, but for me bugs are not animals and therefore need not be afforded the same GOTs considerations. Any way you cut it silk yarn comes from the silkworm. If this causes you concern, search out fiber alternatives as even peace silk is not completely vegan-friendly.
A Tale of Two Princesses
Legend holds that a princess was enjoying a cup of tea in the garden when a silk cocoon dropped into her cup. The warm tea loosened the cocoon “glue” and as she pulled it out, she was first to see the lustrous and strong fiber that comprised it. This secret production stayed hidden behind the Great Wall of China for centuries! Enter the second princess. Centuries after the first discovery, this princess acted as a smuggler and brought silkworm eggs out of China into the rest of the world. Silk production was no longer privatized to China. This caused ramifications throughout the silk industry and introduced competitive global trade!
Little has changed over the millennia in the method of converting cocoons to silk strands since that initial hot tea water bath. The most common method is still boiling. Not only does the water bath remove the inhabitant, it also helps remove some of the “glue” the silkworm used when constructing it’s cocoon. Approximately 3,000 cocoons are used to make one yard of silk (How Silk Is Made “Raw Material”). These lengths are spun together to make silk yarn.
Tussah silk is made from the wild Antheraea mylitta moth, rather than the Bombyx mori caterpillar. The major difference in the two is diet – silkworms eat Mulberry leaves exclusively and the wild moths have a wider diet including a preference for oak leaves. This diet difference results in textural differences in the cocoon. The mulberry diet results in a smooth and fine thread, whereas the oak diet is more textured and rougher. “At a microscopic level the cross-section of the mulberry silk filaments are circular, while the cross-section of tussah is an elongated oval, which results in flatter silk fibres” (Wild Fibres.CO). Tussah silk also has a honey colored natural base rather than mulberry silk’s white. Even though Tussah silk is called wild, the production cycle results typically from a moth breeding program.
Ahimsa silk (Eri silk, aka Peace Silk) is a method of silk production where an attempt is made to preserve the life of the bug while still extracting as complete a single strand as possible. When a moth or butterfly emerges from the cocoon it eats its way out thus breaking the single long strand into hundreds of short strands, which means for yarn makers, knots in the yarn. Peace silk seeks to help the moth emerge without such damage. In many cases, it allows the natural escape route, but not in all. A claim is made that the moth enjoys it’s normal “life-cycle” and is therefore okay. However, when speaking of commercial production, the bugs have been so genetically modified through selective breeding that they live only about 3 days and are unable to fly due to their larger than natural size. Without humans providing food, they emerge only to starve. Also, there is the offspring to consider: “You see, after emerging from the cocoon, moths mate and the females each lay hundreds of eggs. …most of their offspring will die from starvation or dehydration within a few days of birth. Since that’s not much better than being boiled alive, animal activists consider peace silk as inhumane as conventional silk.” (Note: most of the sites I learned from are from the last time I researched silk nearly 8 years ago and are no longer around. Recent searches show little about peace silk. Quote comes from Greenopedia)
Working with Silk Yarn
Silk is the only yarn that dictates a mandatory manicure before using… it likes to catch on the tiniest cuticle or hang nail. The smooth and well, yes, silky texture slides easily through your fingers. However, this yarn has little to no elasticity. So, while it behaves a little like cotton in enjoying a nice relax after washing, the unknit yarn will not expand or stretch even when pulled vigorously! “Not only does it look lustrous and feel luxurious, but it is also lightweight, resilient and extremely strong – one filament of silk is stronger then a comparable filament of steel!” (How Silk Is Made “Background”)
Check out my blog, “Luxury in Fiber”, for the yarn review of Mora.
Since silk comes from a cocoon, which is produced by a bug (most typically a caterpillar), its inherent eco value is null. However, when crafting with silk yarn, you can still get residual eco value from selecting a yarn from a yarn company with a positive eco value. For instance, the one I often use, Mora from Malabrigo, gains its eco value from the socially responsible and environmentally friendly production process Malabrigo yarns employs. The family owned company is committed to sustainability through solar power heating, low water use, consciously using as few chemicals as possible, using renewable wood pellets, and meeting Oeko-Tex 1907/2006 CE standards. Read more on their about page here.
BBC “Wild China” Episode 4 “Beyond the Great Wall” https://www.bbc.co.uk/programmes/b00bz1cf