Natural Fibre Clothing Guide: What to Look For

Most of your wardrobe is probably plastic and you don't even know it. This is the straight-talking natural fibre clothing guide: what the good fabrics are, which ones are pretending, and how to actually find clothes made from real materials.

What Counts as a Natural Fibre?

A natural fibre comes from a plant or an animal. That's it. No lab, no petroleum refinery, no chemical bath. Humans have been wearing these for thousands of years, and they're still better than the plastic alternatives the fashion industry keeps pushing.

Plant-based (cellulose) fibres

• Cotton — from the cotton plant's seed pod
• Linen — from the flax plant's stem
• Hemp — from the hemp plant's stem
• Jute — from the jute plant's bark

Animal-based (protein) fibres

• Wool — sheep fleece
• Silk — silkworm cocoons
• Cashmere — cashmere goat undercoat
• Alpaca — alpaca fleece

The key thing all natural fibres share: they biodegrade. They don't shed microplastics into your water supply. They don't sit in a landfill for 200 years. When they're done, they break down. Revolutionary concept, apparently.

Cotton

Cotton is the world's most used natural fibre, and for good reason. It's soft, breathable, absorbent, and comfortable against skin. It's the baseline that polyester keeps trying (and failing) to replace.

Pros

• Breathable and moisture-absorbent
• Soft against skin — great for sensitive skin and allergies
• Biodegradable
• Easy to wash and dye
• No microplastic shedding

Cons

• Conventional cotton uses a lot of water to grow
• Heavy pesticide use in non-organic farming
• Can shrink if you're not careful with heat
• Wrinkles more than synthetics (but who cares, honestly)

Organic vs conventional cotton

Organic cotton uses no synthetic pesticides or fertilisers, relies on rain-fed irrigation where possible, and is better for soil health. Is it perfect? No. But it uses roughly 88% less water and 62% less energy than conventional cotton. If you see GOTS-certified organic cotton, that's the real deal. If a brand just says "made with organic cotton" without certification, be sceptical.

Linen

Linen is the fabric overachiever. It's made from flax, one of the oldest cultivated plants on Earth, and it produces a textile that's absurdly good at keeping you cool.

Why linen is excellent

• Thermoregulating — feels cool in summer, insulating in winter
• Incredibly durable — actually gets softer and stronger with each wash
• Moisture-wicking — absorbs up to 20% of its weight in moisture before feeling damp
• Naturally antibacterial — resists odour better than cotton
• Low environmental footprint — flax needs minimal water, no irrigation, and grows in poor soil
• Fully biodegradable

The only genuine downside is that linen wrinkles. But here's the thing: wrinkled linen looks good. That's the whole aesthetic. If you're ironing linen, you've missed the point.

Wool

Wool is nature's technical fabric. Before "performance textiles" became a marketing term for plastic, wool was doing everything synthetics claim to do — and actually biodegrading afterwards.

• Warm when wet — wool retains heat even when damp, unlike cotton or synthetics
• Breathable — regulates body temperature in both cold and warm conditions
• Naturally odour-resistant — you can wear merino wool for days without it smelling
• Fire-resistant — naturally, without chemical treatment
• Biodegradable — decomposes in soil within months
• UV protective — blocks more UV than most fabrics

Merino wool is the standout for clothing. It's fine enough to wear against skin without itching, and it's the best base layer material in existence. Yes, better than any synthetic "performance" fabric.

Silk

Silk is a protein fibre spun by silkworms, and it's been a luxury textile for roughly 5,000 years. There's a reason it stuck around.

• Incredibly smooth — the gold standard for feel against skin
• Naturally temperature-regulating — cool in summer, warm in winter
• Strong for its weight — stronger than steel by weight (though you probably won't test this)
• Hypoallergenic — resists dust mites and mould
• Biodegradable

The downsides: it's expensive, requires careful washing, and conventional silk production raises animal welfare questions. Peace silk (ahimsa silk) is an alternative where the moth is allowed to emerge naturally before the cocoon is harvested.

Hemp

Hemp is the most underused natural fibre in fashion, and that's a shame because it's absurdly sustainable.

• Grows fast — reaches harvest in 80-120 days
• Needs almost no water — a fraction of what cotton requires
• No pesticides needed — hemp naturally resists pests
• Improves soil — actually returns nutrients to the ground it grows in
• Extremely durable — hemp fibres are stronger than cotton
• Gets softer over time — like linen, improves with washing
• Naturally UV-resistant and antimicrobial

Hemp used to have a reputation for feeling like burlap. Modern hemp textiles have fixed that. Blended with organic cotton or processed properly, hemp fabric is comfortable, breathable, and genuinely excellent. The reason you don't see more of it is historical regulation and branding, not quality.

The Semi-Naturals: Viscose, Lyocell, Modal

Here's where it gets murky. Viscose, lyocell (often branded as Tencel), and modal are all made from wood pulp — usually eucalyptus, beech, or bamboo. So they start natural. But the process to turn wood into wearable fibre involves serious chemical processing.

Viscose (Rayon)

The original semi-synthetic. Wood pulp is dissolved in chemicals (including carbon disulphide, which is toxic) and extruded into fibres. The result feels nice — silky, breathable, drapes well — but the manufacturing process can be environmentally destructive, especially when it drives deforestation or dumps chemicals into waterways.

Lyocell (Tencel)

The better version. Same concept — wood pulp to fibre — but lyocell uses a closed-loop process where 99%+ of the solvent is recovered and reused. TENCEL-branded lyocell from Lenzing uses sustainably sourced wood. If you're going to wear a semi-synthetic, this is the one.

Modal

Similar to lyocell but made specifically from beech wood. Softer than cotton, good moisture management. Manufacturing impact depends heavily on the producer — Lenzing's Modal is reasonably sustainable; generic modal from unknown sources, less so.

Natural vs Synthetic: The Quick Comparison

If you want the cheat sheet, here it is:

Property	Natural Fibres	Synthetic Fibres
Source	Plants and animals	Petroleum (crude oil)
Biodegradable	Yes — months to a few years	No — 200+ years
Microplastics	None	Up to 900,000 per wash
Breathability	Excellent	Poor (traps heat & moisture)
Skin-friendliness	Hypoallergenic, gentle	Can irritate sensitive skin
Odour	Naturally resistant (esp. wool, linen)	Retains odour quickly
Durability	High (linen, hemp, wool last years)	Moderate (pills and degrades)
Cost	Higher upfront	Cheap to produce
End of life	Composts naturally	Landfill forever

The pattern is clear. Natural fibres win on almost every measure that matters for your health and the environment. Synthetics win on price, which is why fast fashion loves them. That's the whole game.

For a deeper look at the worst offender, read our guide to polyester and what it's doing to your clothes and the environment. And if you want to understand the microplastics problem, we've covered that too.

How to Find Natural Fibre Clothing Online

Here's the problem: even if you know what to look for, finding natural fibre clothing online is a pain. Brands bury fabric composition deep in the product page. You'd have to click into every single item, scroll to the details section, and read the fine print. Nobody does that for 40 items on a category page.

That's exactly why we built Fibr.

Fibr is a free Chrome extension that shows you the fabric composition of every garment right on the product image — as you browse. Green badge for natural fibres. Yellow for mixed. Red for mostly synthetic. No clicking, no scrolling, no guessing.

• Works on Zara, H&M, and Mango (more coming)
• Completely free, no account needed
• Spot the cotton pieces instantly. Skip the polyester. Done.