Cupro (Vegan Silk)
A silky, breathable regenerated cellulose fibre made from cotton linter waste in a closed-loop process — often marketed as 'vegan silk'.
What it is
Cupro (cuprammonium rayon) is a semi-synthetic fibre spun from the tiny cotton linters left on the seed after ginning. The linters are dissolved in a copper-ammonia solution, extruded into filaments, and the solvents are recovered and recycled in a closed-loop system pioneered by Asahi Kasei's Bemberg™ mill in Japan.
Why it matters
Cupro turns a cotton by-product that would otherwise be waste into a silk-like fabric with none of the animal welfare issues of silkworm silk. When produced in a certified closed-loop facility, solvent recovery is above 99%, and the finished fibre is biodegradable and compostable under industrial conditions.
Upsides
- Uses cotton linter — a waste stream from conventional cotton production
- Closed-loop solvent recovery (>99%) at Bemberg's Japanese mill
- Fully biodegradable and compostable at end of life
- Vegan and cruelty-free alternative to mulberry silk
- Breathable, thermoregulating, hypoallergenic, machine-washable
Trade-offs
- Only one certified closed-loop producer worldwide — most 'cupro' on the market has no traceable origin
- Uncertified cupro can be produced with heavy metal (copper) discharge to waterways
- Still a resource-intensive chemical process compared to lyocell
- Often blended with elastane or polyester, which kills biodegradability
What to look for on the label
'Bemberg™ by Asahi Kasei' on the composition label, or a supplier chain-of-custody document. Look for OEKO-TEX Standard 100 certification and 100% cupro content — avoid blends with synthetics if biodegradability matters to you.
Better or comparable alternatives
Frequently asked
Is cupro fabric sustainable?+
Bemberg™ cupro from Asahi Kasei is one of the more sustainable silk alternatives — it upcycles cotton linter waste and recovers over 99% of its solvents in a closed loop. Generic, uncertified cupro is not: it can discharge copper and ammonia into waterways. Always check for the Bemberg™ trademark or a verified chain-of-custody document.
Is cupro a vegan silk?+
Yes. Cupro is plant-based (cotton linter cellulose) and made without silkworms, so it is fully vegan. It drapes and feels similar to silk, but it's a regenerated cellulose fibre, not an animal protein.
Is cupro biodegradable?+
Pure 100% cupro is biodegradable and compostable under industrial conditions in a few months. Blends with polyester, nylon, or elastane are not — always check the composition label.
Cupro vs lyocell — which is more sustainable?+
Lyocell (Tencel) generally has a lower environmental footprint because its NMMO solvent process is simpler and its FSC-certified wood pulp feedstock is traceable. Cupro wins on feedstock (using a waste stream) but only when produced in the Bemberg™ closed-loop mill.
Shop cupro (vegan silk) picks
Other materials
How to judge Cupro (Vegan Silk) in a real product
A material is never good or bad on its own — it is good or bad for a specific job, at a specific lifespan. Cupro (Vegan Silk) performs well where its strengths match how the product is used, and poorly where a different fibre or feedstock would last longer with less impact.
The two questions that decide most of the footprint are how long the product survives normal use, and what happens to it afterwards. A durable item kept for a decade almost always beats a lower-impact material replaced every year, which is why we weight lifespan alongside sourcing.
Blends complicate everything. Mixed materials are much harder to recycle because the components must be separated chemically, so single-material products — or blends above roughly 95% one input — are usually the better end-of-life choice.
Cupro (Vegan Silk) vs common alternatives
| Factor | Cupro (Vegan Silk) | Conventional alternative | What to look for |
|---|---|---|---|
| Durability | Depends on weave/grade | Often optimised for cost | Warranty, GSM or gauge |
| Chemical load | Lower when certified | Often untested residues | OEKO-TEX STANDARD 100 |
| Traceability | Traceable when certified | Rarely disclosed | Named mill or supplier list |
| End of life | Best when unblended | Usually landfill | Single-material construction |
| Microplastic shedding | None if natural | High for loose synthetics | Fibre type on the label |
Buying checklist for Cupro (Vegan Silk)
- Match certification to fibreGOTS for organic naturals, GRS for recycled synthetics, FSC for wood and paper.
- Check the composition percentage“Contains organic” can mean 5%. Look for the exact number.
- Prefer repairable constructionReplaceable parts and standard fastenings extend life far more than material choice.
- Read care instructionsCold-wash, line-dry items keep their finish and shed less over time.
How to verify a Cupro (Vegan Silk) claim in three minutes
- Find the composition label. Exact percentages, not marketing adjectives.
- Look up the certificate. Search the certifier's public register for the brand or licence number.
- Check the scope and expiry. Confirm the certificate is current and covers the product you are buying.
- Compare lifespan. Pick the option you will realistically keep longest at similar quality.
Frequently asked
Is Cupro (Vegan Silk) better than conventional options?+
Usually yes on the specific dimension it is certified for, and only when the certification is current and covers the product. It is not automatically better across every dimension — durability and end-of-life handling still matter.
Which certification should I look for with Cupro (Vegan Silk)?+
Match the mark to the material family: GOTS for organic natural fibres, GRS or RCS for recycled content, FSC for wood-based inputs, and OEKO-TEX STANDARD 100 for chemical residue on finished goods.
Does a blend ruin the benefit?+
It reduces it. Blends are harder to recycle and often shed more. If a blend is unavoidable, prefer a high single-fibre share and a construction that can be repaired.