Is Silk Ethical? Everything You Need to Know

Silk is having a moment in the knitting world. And with that comes a question we see more and more often: is silk ethical?

The short answer is: it depends entirely on the type. And most of what gets labelled ethical silk online is not what people think it is.

Here is everything you need to know.

How conventional silk is made

All conventional silk starts the same way. Silkworms spin cocoons from a single continuous filament that can be up to a kilometre long. To preserve that filament intact, the cocoon is plunged into boiling water before the moth inside can emerge and break the thread. The silkworm does not survive this process.

This is how the vast majority of silk in the world is produced, including most of what you will find in yarn shops, fabric stores, and luxury fashion houses. It is not hidden information, but it is rarely talked about directly.

Mulberry silk

Mulberry silk is made from silkworms that feed exclusively on mulberry leaves. It produces the smoothest, most lustrous filament of any silk type. It is also the most widely farmed and the most affordable of the premium silks.

The silkworms are killed during processing. There is no version of standard mulberry silk where they are not.

When you see mulberry silk marketed as sustainable, what that usually means is that the farming practices are more responsible, the dye processes are cleaner, or the supply chain is more transparent. It does not mean the silkworms survive. These are meaningful improvements, but they are not the same thing as cruelty-free.

Bourette silk

Bourette silk, also called silk noil or schappe silk, is made from the short fibres left over after the long filaments have been reeled off the cocoon. It is a byproduct of conventional silk production.

Bourette is sometimes assumed to be more ethical because it uses waste material. In one sense that is true: it makes use of fibre that would otherwise be discarded, which reduces waste. But the silkworm still did not survive the process that produced it. Bourette is more sustainable in terms of material use. It is not cruelty-free.

It does have its own character worth celebrating. Matte, slightly nubby, warm and earthy. Nothing like what most people picture when they think of silk. And significantly more affordable than mulberry.

Tussah silk

Tussah silk comes from wild silkworms that feed on oak, juniper and other leaves rather than farmed mulberry. Because they are wild rather than farmed, the ethical picture is more complex and more nuanced.

Some tussah silk is harvested from abandoned cocoons after the moth has naturally emerged, which means the worm survives. Other tussah is harvested conventionally. The distinction matters and is worth asking about if this is important to you.

Tussah has a coarser, more textured hand than mulberry and a naturally warm, golden tone. It is a beautiful fibre with a distinctive character.

Eri silk

Eri silk comes from a different species of silkworm entirely, one that spins an open-ended cocoon. Because the cocoon is open at one end, the moth can emerge naturally without breaking the filament. The fibre is harvested after the moth has left.

This makes eri silk genuinely cruelty-free in a way that mulberry silk is not. It is sometimes called the fabric of peace in the regions of India and Northeast Asia where it is traditionally produced. The texture is softer and more matte than mulberry, with a warmth that is closer to wool than conventional silk.

Eri is still niche in the western knitting market but it is increasingly available and worth watching.

Ahimsa silk

Ahimsa silk, also called peace silk, is the most rigorously ethical option available. The process specifically ensures the moth emerges from the cocoon before the fibre is harvested. The broken filaments are then spun rather than reeled, which changes the texture considerably.

Because the filament is broken rather than continuous, ahimsa silk has a softer, more diffused character than mulberry. It lacks the high sheen but has a warmth and depth of its own.

It is also significantly rarer and more expensive than any other type of silk. Genuine ahimsa certification requires careful supply chain verification. If you see it at a price that seems too good to be true, it probably is.

So what is actually ethical?

Here is the honest answer.

If your concern is the survival of the silkworm, the only silk types that genuinely address that are ahimsa, eri, and wild-harvested tussah. Everything else, including mulberry and bourette, involves conventional sericulture where the silkworm does not survive.

If your concern is environmental impact more broadly, bourette and tussah have strong cases to make. Bourette uses fibre that would otherwise be wasted. Tussah comes from wild rather than intensively farmed silkworms.

If your concern is supply chain transparency, we would encourage you to research the mills directly. We share the name of every mill we source from. That information is yours to investigate. We are a small business and we cannot verify every step of every supply chain ourselves. What we can do is be open about where our yarn comes from and let you make your own informed decisions.

There is no perfect answer. But there is a more honest conversation to be had, and we would rather have it directly than hide behind vague sustainability language.

What we stock

We currently stock bourette silk and a cashmere and mulberry silk blend. We are transparent about what these fibres are and how they are made. We are actively looking at eri and tussah for future additions to the range.