Is silk vegan? Why vegans don’t wear silk

Author: Lex Rigby

Read Time:   |  15th June 2021

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Have you been wondering is silk vegan? Lex Rigby from Viva! navigates the labyrinthine twists involved in silk production to reveal why silk is not vegan.


When it comes to fashion, many animal-derived fabrics are thought to be mere by-products of the meat industry.

Take leather, it’s simply not true that the preserved skin of dead animals used in jackets and handbags would go to waste if we didn’t make use of it in other ways. For anyone that’s bravely sat through Earthlings, you’ll know that couldn’t be further from reality.

Animal skin is big business in its own right, and in some instances is much more valuable than the animal’s flesh. Unlike leather though, silk isn’t made from animal flesh – it’s in fact caterpillar spit (or saliva) and millions of silkworms are boiled, roasted, or frozen alive to cultivate it.

Is silk vegan?

When it comes to fashion, many animal-derived fabrics are thought to be mere by-products of the meat industry.

Take leather for example. It’s simply not true that leather used in jackets and handbags would go to waste if we didn’t make use of it in other ways. For anyone that’s bravely sat through Earthlings, you’ll know that couldn’t be further from reality.

Animal skin is big business in its own right, and in some instances is more valuable than the animal’s flesh.

But unlike leather, silk isn’t made from animal flesh. In fact, silk is made with caterpillar spit (or saliva).

But why can’t vegans wear silk if it’s just caterpillar spit you ask? Shockingly, millions of silkworms are boiled, roasted or frozen alive in the process of cultivating spit.


Cocooning caterpillars

In commercial use, silk is almost entirely derived from the cocoons of domesticated silkworms called ‘bombyx mori’.

Silk is an extremely thin, strong, thread-like fibre that some insects and spiders produce to build cocoons and webs. Due to its smooth, soft texture, silk is highly sought after for clothing. The popular luxury material is typically woven into lightweight blouses, dresses, scarves, ties, underwear, and pyjamas.

It is also widely used by the textile industry for sheets, pillowcases, and other soft furnishings; including artificial flowers.

Before transforming into adult moths, young silkworms naturally build cocoons from one continuous white or yellow strand of silk. Impressively, the average length of these silk strands is around 1,400 metres in length.

This stage of their four-part life cycle is known as the pupa and metamorphosis and will last about two weeks. Cocoons can take three to eight days to build and keep the silkworms safe as they develop into adulthood.

Wild silk moths (bombyx mandarina) are not as commercially viable in the production of silk. Sadly this means they live incredibly short lives, only one week in most cases – giving them just enough time to reproduce.

Domestic silk moths, on the other hand, are entirely dependent on humans for reproduction as a result of millennia of selective breeding and are unable to fly.

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"It costs the lives of about 15 silkworms to create a single gram of silk"


Commerical silk production

Silk in the fabric industry is produced on an industrial scale by breeding silkworms on intensive moth farms. Once they’ve carefully constructed their cocoons, the pupas (transforming silkworms) are killed, never to emerge as moths.

It costs the lives of about 15 silkworms to create a single gram of silk. So, to make an entire wedding dress, we’re talking about the lives of thousands of silkworms.

To break through their carefully constructed cocoons, the adult moths first release a fluid called cocoonase, which partially dissolves the silk and gummy outer residue, and then they dig their way out with their claws.

The cocoonase damages the silk’s integrity, so to preserve the fibre, the pupa is killed with hot air, steam, or boiling water.

Ahimsa silk

A non-kill method of silk production does supposedly exist and is otherwise known as Ahimsa silk.

In the production of Ahimsa silk, wild (rather than domesticated) silk moths are bred and the pupas are meant to be given the chance to complete the metamorphosis to emerge as adult moths.

Rather than break through the cocoon with the help of cocoonase, which damages the silk, the Eri silkworms used in Ahimsa production leave a small opening in the cocoon through which they crawl as moths.

Given that it takes an extra 10 days to produce silk in this way, it’s doubtful this process would take off commercially. Another issue is that the silk is generally considered inferior.

Unlike silk from domesticated silkworm cocoons that is unreeled, the fibre of Ahimsa silk is spun like cotton or wool, which impacts the quality.

Moreover, despite the ‘no-kill’ philosophy behind Ahimsa silk, the health and wellbeing of farmed silkworms is still a concern.

Some producers claim the silk is wild-harvested rather than farmed. But as this is completely economically unviable it’s difficult to believe. Other producers indicate that most Eri cocoons are cut open and the pupa removed by hand to be used as a food source or fertilizer, which seems much more likely.

Vegan silk alternatives

Even by opting to buy Ahimsa silk, you can’t be sure of the process involved to produce it. Also, Ahimsa silk still exploits animals in ways that vegans fundamentally oppose.

The best way to avoid contributing to the mistreatment of silkworms is to not buy products made with silk.

Cruelty-free, plant-based materials like polyester, nylon, and rayon easily replicate silk and are fairly widespread and cheaply available.

Rayon is made from cellulose –a natural wood pulp fibre – and can be dyed a range of colours. However, like polyester and nylon, it may be subjected to lots of non-environmentally friendly chemicals in the process.

Lyocell and modal, on the other hand, are types of rayon fibres that are dyed using chemicals free from harmful solvents. As well as being made with eco-friendly materials, they are also produced in a closed-loop production cycle.

This means that the chemicals are captured and reused over and over again. Tencel is a certified form of lyocell that is guaranteed to be made from sustainable wood pulp. Therefore is a much more eco-friendlier option for fabrics.

While it may seem like there’s no perfect alternative in this case, synthetic options avoid the deaths of millions of animals.

A huge amount of investment and research is underway by companies to make eco-friendly fabrics. As a result, they are competing to develop innovative, sustainable and eco-friendly materials on a commercial scale.

Microsilk by Bolt Threads, made from a yeast, sugar and water fermentation process, is just one example.

Now you’ve found out the answer to ‘is silk vegan?’, find out here if faux fur or real fur is better for the environment.

Written by

Lex Rigby

Lex joined Viva! in 2018 after more than a decade campaigning to defend, conserve and protect marine wildlife. As Viva!’s Head of Investigations she is responsible for coordinating hard-hitting investigations to support Viva!’s ground-breaking campaigns, with the ultimate aim of growing veganism in the UK and increasing support for Viva!.

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