Organic cotton, recycled polyester and Tencel are the materials most brands ask about first. They are also the ones most frequently misrepresented. Here is what each one actually does, where it comes from, and what it costs to source credibly.
Organic cotton
Organic cotton is grown without synthetic pesticides and fertilizers, and processed through a chain that is certified to the organic standard from farm to finished fabric. The strongest claim is GOTS-certified organic cotton — not "organic" by a supplier's word.
- Good for: knit and woven apparel where a natural fibre is part of the brand story.
- Watch for: the price gap versus conventional cotton, and sufficient supply at your quantities.
- The standard: GOTS chain of custody, with the fibre origin named in the documentation.
Recycled polyester
Recycled polyester (rPET) is most often made from post-consumer PET bottles. It is not a circular textile story on its own — bottles are made into fibre, fibre into fabric, fabric into garment, then it leaves the textile stream. GRS is the certification that tracks it.
- Good for: knit fabrics, fleece, outerwear, swim and activewear where polyester is the functional choice.
- Watch for: the microplastic question, and the fact that rPET is a finite supply tied to bottle collection.
- The standard: GRS for chain of custody; the recycled content claim must match the certification.
Tencel (lyocell)
Tencel is a branded lyocell — a cellulose fibre made from wood pulp in a closed-loop solvent process. It is the fibre most associated with a softer drape and a lower-impact process than conventional viscose.
- Good for: lightweight knits and wovens where drape, hand-feel and a sustainable story matter.
- Watch for: the fibre is premium-priced, and the finishing and dye still matter for the overall picture.
- The standard: the fibre is branded and traceable; the downstream processing still matters.
How to specify
Decide on the fibre by hand-feel, performance and price first, then choose the certification that matches the claim. Don't choose the certification first and then look for a fibre that happens to carry it — the result is a weaker product and a weaker claim.
The most credible sustainable fabric is the one whose fibre, processing and certification all match the label you put on it.