How to Read a Material Label
Updated Aug 19, 2026 2 mins read
Edited by Urša Satler
The composition label sewn into a garment is the single most informative thing on it. It is also legally regulated in most countries; fiber percentages must add up to 100% and the names must be the recognised generic terms (cotton, linen, wool, polyester, elastane). Marketing copy on the swing tag is not regulated. The composition tag is.
What the percentages tell you
A label that reads 100% cotton means the cloth is single-fiber cotton. A label that reads 60% cotton, 40% polyester is a blend, and the polyester will not breathe, will not biodegrade, and will shed microplastic in the wash. A label that reads 97% cotton, 3% elastane is single-fiber cotton with a small stretch component, common in fitted styles and broadly fine.
The order is meaningful. Fibers are listed in descending order of weight, so the first fiber listed is the dominant one.
What the certifications confirm
A certification logo on the label or swing tag (GOTS, OEKO-TEX, OCS, RWS, bluesign, Fairtrade) is an independent verification of one specific claim. The claim varies by certification: GOTS covers organic content and processing chemistry; OEKO-TEX certifies the finished cloth is free of harmful substances; RWS covers wool farming practices. None of these certifications are blanket "ethical" stamps. Each verifies a specific scope.
A swing tag that says "sustainable" or "eco-friendly" without a logo is not verified by anyone outside the brand.
What is usually missing
Most composition labels do not tell you:
- Where the fiber was grown
- Where the cloth was woven
- Where the garment was sewn
Some brands publish this on their website. That is what we mean by "transparent sourcing" when you see it on a brand page on this site. Most brands publish only the country of final assembly, which is the legal minimum.
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About the editor
Urša Satler is the founder of Purefect Choice, an online non-toxic goods shop in Slovenia. She stocks what she and her family actually need and use themselves, chosen on material composition and certification.
She started MaterialFilter for a plainly selfish reason: she was tired of checking labels in shops one garment at a time, and tired of hunting for fibre content buried five clicks deep on a product page, usually to discover that a beautiful dress was mostly polyester. MaterialFilter does that checking once, up front, so the composition is the first thing you see instead of the last thing you find.
She sets the standard this site scores against and owns its editorial direction. What she brings to it is the habit of reading a composition label before anything else (daily, for her own family and the shop she runs) and one rule that keeps that habit honest: every claim on MaterialFilter is meant to be checkable against a certification body's own public register, so you never have to take her word for it.