Reference library
Sustainable materials, decoded
What each material actually is, what certifications mean on the label, and the trade-offs greenwashing won't tell you about.
The most reliably sustainable everyday materials are organic cotton, hemp, linen, lyocell (TENCEL), FSC-certified wood and genuinely recycled metals and glass. Each is judged on how it is grown or extracted, how it is processed, how long it lasts and what happens at end of life — durability usually matters more than the raw material name.
- Conventional cotton uses roughly 2,700 litres of water per T-shirt.
- Hemp needs about half the water of cotton and no pesticides.
- Lyocell uses a closed-loop solvent system that recovers over 99% of solvent.
- Recycled polyester still sheds microplastics in the wash.
- Bamboo viscose is chemically processed; bamboo linen is not.
- The longest-lasting product is usually the lowest-impact one.
Organic Cotton
Cotton grown without synthetic pesticides or GMOs, certified by GOTS or OCS.
Recycled Polyester (rPET)
Polyester fibre made from recycled PET, usually post-consumer plastic bottles.
Hemp
Fast-growing bast fibre that needs little water, no pesticides, and improves soil.
FSC-Certified Wood
Wood and paper from forests independently certified for sustainable management.
Lyocell (Tencel)
Closed-loop wood-pulp fibre with 99% solvent recovery, silky drape, biodegradable.
Bamboo
Fast-growing grass — sustainable as a raw material, often problematic as fabric.
Recycled Aluminium
Infinitely recyclable metal that uses 95% less energy than virgin production.
Cork
Bark harvested without felling the tree — renewable every 9 years.
There is no perfect material — only better trade-offs
Every material trades one impact against another. Organic cotton removes pesticides but often needs more land. Recycled polyester diverts bottles from landfill but sheds microfibres into UK waterways with every wash. Wool is durable and biodegradable but is an animal product we exclude entirely.
The useful question is not 'which material is green?' but 'which material lasts longest for how I will actually use this?'. A synthetic jacket worn for ten years beats an organic cotton one replaced every eighteen months.
- Growing impact: water, land, pesticides, fertiliser
- Processing impact: chemicals, energy, dye and effluent
- Use impact: washing temperature, microfibre shedding, repairs
- End of life: recyclable, compostable, or landfill only
What to look for on a UK product listing
Good listings state the fibre percentages, the certification and the country of manufacture. Weak listings say 'eco fabric' and show a leaf. If a listing will not tell you the composition, assume the composition is not a selling point.
For wood and paper, FSC or PEFC chain-of-custody codes are the standard. For textiles, GOTS covers organic fibre plus processing and some labour criteria, which makes it the single most informative textile mark on the UK market.
Material trade-offs compared
| Material | Main strength | Main weakness | Look for |
|---|---|---|---|
| Organic cotton | No synthetic pesticides, soft and breathable | High water and land use | GOTS or Soil Association |
| Hemp | Low water, low input, very durable | Coarser handle, fewer UK suppliers | GOTS or EU-grown |
| Linen (flax) | Low input, biodegradable, long-lived | Creases, higher price | European Flax |
| Lyocell / TENCEL | Closed-loop solvent, soft, biodegradable | Energy-intensive, brand-dependent | TENCEL branded fibre |
| Recycled polyester | Diverts waste, strong and quick-drying | Microplastic shedding, not endlessly recyclable | GRS certification |
| Bamboo | Fast-growing crop | Viscose processing is chemical-heavy | Bamboo linen or closed-loop lyocell |
| FSC wood | Responsible forestry, repairable, durable | Says nothing about factory labour | FSC 100% or FSC Mix code |
How to choose the lower-impact option
- 1Decide how long you need the item to last, honestly.
- 2Read the full composition, not the headline fibre.
- 3Prefer single-fibre items — blends are far harder to recycle.
- 4Check for a processing certification (GOTS, GRS, FSC), not just a fibre name.
- 5Check care instructions: cold-wash, line-dry items cut lifetime impact sharply.
- 6Plan the end of life — repairable, resellable or recyclable in your area.
Frequently asked questions
Is bamboo fabric sustainable?
It depends entirely on processing. Bamboo grows fast with little water, but most bamboo clothing is bamboo viscose, made by dissolving pulp in harsh chemicals. Bamboo linen and closed-loop lyocell versions are far better; unlabelled 'bamboo' on a UK listing usually means conventional viscose.
Is recycled polyester better than virgin polyester?
Yes, on balance. It uses roughly 30–50% less energy and diverts plastic from landfill, so it is the better choice where synthetics are needed. It still sheds microplastics when washed, so use a filter bag and wash cold to limit release into UK waterways.
What is GOTS certification?
The Global Organic Textile Standard certifies that a textile contains at least 70% certified organic fibre and that processing meets environmental and social criteria, including restricted chemicals and worker protections. It is the most informative single textile certification available in the UK.
Does buying second-hand beat buying sustainable materials?
Usually yes. Extending the life of an existing item avoids the entire production footprint, which dominates most products' impact. Buy new when you need durability or hygiene that second-hand cannot provide, then choose the best-certified material available.