Is silk sustainable?

Sustainability is one of those words that gets stamped on everything now, from water bottles to sweatpants, and most of the time nobody explains what it actually means. So when people ask us whether silk is sustainable, we don't want to hand over a slogan. We want to give you the real answer, including the parts we wrestled with ourselves.

Here it is: silk can be one of the better choices for your bed, but only certain silk. How the trees are grown, how the fiber is processed and how the people making it are treated matter more than the word "silk" on the label.

First, what are the alternatives made of?

Most pillowcases are made from one of three things: cotton, satin or silk.

Cotton is a plant, which sounds wholesome until you look at how most of it is grown. Conventional cotton relies heavily on chemical inputs. In its 2025 survey of US cotton farms, the USDA found herbicides were applied to 88% of planted cotton acres and insecticides to 39%. That's before you get to the fertilizer, the irrigation and the bleaching and dyeing that happen later.

Satin is the one that surprises people. Satin isn't a fiber at all. It's a weave, a way of arranging threads so one side is glossy. Most satin pillowcases are woven from polyester, and polyester is a plastic made from petroleum. It's inexpensive and it's shiny, but every wash can shed tiny synthetic fibers into the water, and when it's thrown away it doesn't break down the way natural fibers do.

Silk is a natural protein fiber, spun by silkworms that feed on mulberry leaves. It's strong, it lasts for years with good care, and at the end of its life it's a natural material rather than plastic.

So is silk automatically the good guy?

No, and anyone who tells you otherwise is skipping a few chapters. Conventional silk can come from mulberry trees grown with synthetic pesticides and fertilizers. It can be processed with harsh chemicals and dyes, with wastewater going straight back into rivers. And it can be made in facilities where nobody is checking working hours or safety.

Some lifecycle studies have also scored silk as a high-impact fiber, mostly because of the energy used in raising silkworms and processing the cocoons. The silk industry has challenged those scores, and the debate is still going. We'd rather tell you that than pretend it doesn't exist.

Silk is only as good as the farm and the factory behind it.

That's why, if you care about sustainability, the most useful thing you can do is look past the word "silk" and into the company's practices. What are they certified for? Can they show you? Do they explain what the certifications actually cover?

On our nightstandThe Evevior silk pillowcaseOrganic 6A mulberry silk, 22 momme, in four colors named for Barbados.Take a look

What a GOTS certified facility changes

This is where we can speak for ourselves. Evevior pillowcases are made from organic mulberry silk. Our partner facility is certified GOTS, the Global Organic Textile Standard, is the leading global standard for textiles made from organic fibers, and it follows the fiber from the farm through every step of production.

Here's what that means in practice:

• The mulberry trees are grown organically. No synthetic pesticides, no synthetic fertilizers and no genetically modified plants. Our silkworms are raised on a diet of those organically grown leaves.
• Chemicals are restricted. Harsh processing chemicals aren’t allowed, including toxic heavy metals, formaldehyde and certain dyes.
• Water is treated. Wastewater from wet processing has to be treated before it's released, with strict limits on what it can contain.

• People are protected. The facility is independently audited against International Labour Organization standards: no forced or child labor, freedom of association and the right to collective bargaining, no discrimination, safe and hygienic working conditions and limits on working hours.

Our silk is also certified to OEKO-TEX Standard 100, which looks at the finished fabric itself. Every OEKO-TEX Standard 100 product is tested against a list of over 1,000 harmful substances. 

The silkworm question

We want to be straight with you here, because it's the question we asked ourselves first. In almost all mulberry silk, organic included, the cocoon is heated before the moth emerges, so the silkworm doesn't survive. That's how long, unbroken silk filaments are made, and those long filaments are what give silk its smooth, low-friction surface.

We understand the concern. We sat with it too.

We understand why this matters to people, and we don't think it's a question with a perfect answer. For us, it came down to the whole picture: a natural fiber, grown organically, processed under strict chemical and water rules, made by people whose working conditions are independently audited, and built to last for years instead of a season. Next to a pillowcase grown with heavy chemical inputs or a satin one made from petroleum, organic silk was the most responsible choice we found. We'll keep looking, and we'll keep telling you what we learn.

How to shop for silk that's actually sustainable

Whether you buy from us or anyone else, here's what to look for:

1. 100% mulberry silk. Not "silky," not "satin silk," not a blend.
2. OEKO-TEX Standard 100 for what's in the finished fabric. You can check any certificate number on the OEKO-TEX website.
3. A brand that explains itself. If a company can't tell you where its silk comes from or what its certifications cover, that tells you something too.
4. Quality that lasts. A 22 momme, grade 6A pillowcase that you wash gently and keep for years is better for the planet than three cheap ones that pill by summer.

The bottom line

No fabric comes with zero impact. But you get to choose which impact you're comfortable with, and you deserve the information to choose well. We chose organic silk because, after looking at everything, it was the option we could stand behind.