Bolt Threads is Creating Cruelty-Free Vegan Silk

Bolt Threads is Creating Cruelty-Free Vegan Silk

Silk is an animal by-product that many people fail to consider but the truth of the matter is that more than 66,000 silkworms die in order to produce just one small kilogram.

During one process the silkworms are boiled alive inside of their cocoons in order to harvest the silk. So-called ‘ahimsa silk’ or ‘peace silk’ is not a solution.

Investigations held in India found that the male silkworms were housed in a refrigerator and brought out only for breeding. After breeding had occurred they were then discarded into the trash when they were unable to mate any longer.

The use of silk in the fashion industry is absolutely not eco-friendly. A report done by the Pulse of Fashion found that silk is actually the second most polluting material (after cow’s leather) when it was analyzed from start to finish.


The solution for all of these issues appears to be a new innovation known as synthetic spider silk. (1)

A material innovation company in California, Bolt Threads, has created a synthetic replica of the amazingly resilient silk produced by actual spiders who are nature’s own silk weavers.

Farming spiders for the production of silk was never a viable option as arachnids are far too territorial to be farmed in large sized groups because cannibalism becomes an issue.

However, Bolt Threads has created a way to tap into the spider’s innovative abilities and replicate them without ever having to involve live spiders.

Bolt Threads Microsilk material possesses strength and durability, along with softness just like actual silk created by a spider.

Fashion Engineering

Bolt Threads has developed proteins inspired by actual natural silk through a bioengineering process where genes are inserted into yeast. The yeast ferments with sugar and water and the liquid silk proteins are able to be extracted.

This process is likened to the process used when producing acrylic and rayon – only much eco-friendlier. The original challenge was to transform raw material into usable yarn but it proved to be too thin and fragile.

After many trial and error attempts and years of research, Bolt Threads solved the issue and presented a durable, resilient yarn, which is as supple and soft as silk produced by a spider.


Microsilk is also renewable. The major component is sugar which is obtained from plants that are replanted, unlike polyester, which has always been the usual plant-based replacement for silk and was made using petroleum.

As such, Microsilk has the ability to rival traditional silk, which is not only harmful to the silkworms and the environment but also extremely difficult to care for.

Stella McCartney was the first to pioneer this amazing material. McCartney also refrains from using both fur and leather in her creations. She worked tirelessly with Bolt Threads on a dress she created using Microsilk and then went on to feature it in an exhibit at New York’s Museum of Modern Art.