Food has an ingredient label and people read it. Clothing has one too — it's the small tag inside the seam — and almost nobody does.
It's the one part of a garment that can't market to you. The product page can say "eco-friendly," "conscious," "performance fabric" and "clean." The tag has to say what the thing is made of.
Here's how to read it.
The full fiber reference
| Fiber | Type | Sheds microplastics | Common finishes applied | Against skin |
|---|---|---|---|---|
| Organic cotton | Natural | No | Rarely — GOTS prohibits most | Breathable, absorbent, softens with wear |
| Cotton (conventional) | Natural | No | Wrinkle-free resins, easy-care treatments are common | Same fiber; grown with synthetic pesticides, often finished with formaldehyde-based resins |
| Merino wool | Natural | No | Superwash (a chlorine-based anti-shrink treatment) is common | Naturally odor-resistant and thermoregulating; ultrafine grades (under ~19 micron) don't itch |
| Wool (standard) | Natural | No | Superwash, moth-proofing | Warmer, coarser; itch depends on micron |
| Hemp | Natural | No | Few | Durable, breathable, softens over many washes |
| Linen (flax) | Natural | No | Few | The most breathable natural fiber; wrinkles by nature |
| Silk | Natural | No | Weighting agents on cheap silk | Smooth, thermoregulating, delicate |
| Cashmere | Natural | No | Few | Very fine wool; pills easily |
| Lyocell / TENCEL™ | Semi-synthetic | No | Few | Plant cellulose in a closed-loop solvent process. Smooth, cool, absorbent. The best of the regenerated fibers |
| Modal | Semi-synthetic | No | Few | Regenerated beech cellulose. Soft, drapes well |
| Viscose / rayon | Semi-synthetic | No | Varies | Regenerated cellulose using a harsher process than lyocell |
| Bamboo | Semi-synthetic | No | Varies | Almost always bamboo viscose, not bamboo fiber. The FTC has taken action against brands marketing it as natural |
| Polyester | Synthetic | Yes | DWR, antimicrobial, moisture-wicking, stain-resistant | Plastic. Poor breathability; traps odor, which is why finishes get applied |
| Recycled polyester | Synthetic | Yes | Same as polyester | Still plastic. Sheds identically to virgin polyester |
| Nylon / polyamide | Synthetic | Yes | DWR, antimicrobial | Plastic. Stronger and stretchier than polyester |
| Recycled nylon | Synthetic | Yes | Same as nylon | Still plastic |
| Elastane / spandex / Lycra | Synthetic | Yes | — | Plastic. Three names for the same fiber. Provides stretch and recovery; nothing natural replicates it |
| Acrylic | Synthetic | Yes | — | Plastic. Wool substitute; pills heavily |
| Polypropylene | Synthetic | Yes | — | Plastic. Common in cheap base layers |
The five things a label won't tell you
1. Which half of a blend is which. "Cotton blend" is a garment named after the fiber that sells. The tag has to give percentages — the product page doesn't. Always read the tag.
2. The difference between a fiber property and a finish. Merino resists odor because of what it is. Polyester resists odor because something was sprayed on it. Both get described as "odor-resistant."
3. What was done to the fabric after weaving. Dyes, softeners, anti-shrink treatments and performance finishes don't appear on a fiber content tag. That's what OEKO-TEX Standard 100 certification covers — it tests the finished article against over 1,000 harmful substances.
4. Trims. Waistband elastic, tags and drawcords are usually excluded from the main composition. Nearly every garment made needs some elastane at the waistband — nothing natural delivers stretch recovery that survives hundreds of washes.
What varies is how it's constructed. In a covered or core-spun yarn, the elastane core is wrapped in the natural fiber, so what sits against your skin is cotton or wool rather than the synthetic. In a bare-elastane waistband, it isn't. Both read as "elastane." Only one keeps the synthetic off your skin, and it's worth asking which you're getting.
5. Whether "recycled" changes anything for you. It changes the waste story. It does not change the material touching your skin, or what comes off it in the wash.
The four-line version
- Natural fibers — cotton, wool, hemp, linen, silk. Grown, not extruded. No microplastic shedding.
- Semi-synthetics — lyocell, TENCEL, modal, viscose, bamboo. Plant cellulose, chemically regenerated. Better than plastic, not the same as cotton.
- Synthetics — polyester, nylon, elastane, acrylic. Plastic. Shed microplastics through wear and washing.
- "Recycled" anything synthetic — still plastic.
What to look for instead of a claim
A composition you can read as a sentence: 100% organic cotton. 100% merino wool. 240GSM. Numbers and materials, no adjectives.
Then check the product page for finish words — water-repellent, DWR, stain-resistant, wrinkle-free, antimicrobial, moisture-wicking finish. Each one means a chemical was applied to make the fabric do something the fiber couldn't.
A label with nothing to hide
The Wayve Quad Short, $90:
- Shell: 100% organic cotton, 290GSM brushed terry, GOTS certified
- Liner: 100% merino wool, 165GSM jersey knit
- Finishes: none — no DWR, no antimicrobial, no moisture-wicking treatment
- Trims: covered elastane at the waistband — the elastane is wrapped in the natural fiber, so the synthetic core never sits against skin. Everything else is cotton: the drawstring, the brand tag and the care and material labels.
That last part is deliberate. Almost every garment on the market — including certified organic ones — uses a printed polyester care label, because it's cheaper and takes ink better. It's also the scratchy thing you cut out of the back of your shirt. Wayve's are woven cotton.
The odor resistance comes from the merino. The breathability comes from the cotton. Nothing was added to make either happen.
See the full ingredient breakdown · Shop the Quad Short · Only Tee, $45 · Classic Short, $55
FAQ
Is bamboo fabric natural?
Almost never. Bamboo clothing is nearly always bamboo viscose — cellulose extracted from bamboo and chemically regenerated into fiber. The FTC has taken enforcement action against brands marketing it as a natural fiber. It's better than polyester and it is not cotton.
Does recycled polyester shed microplastics?
Yes, identically to virgin polyester. Recycling changes where the plastic came from, not what it does in your washing machine.
Is elastane in a waistband a problem?
Far less than elastane blended through the body fabric. A waistband is a few grams at your hip; 8% elastane in the main fabric is synthetic across every square inch touching you. Both show up as "elastane," so read which fabric it's attached to.
What's the difference between lyocell, TENCEL and modal?
TENCEL is a brand name for lyocell made by Lenzing. Lyocell uses a closed-loop solvent process that recovers most of its chemicals; modal and viscose use harsher processes. All three are regenerated cellulose.
Why doesn't the tag list dyes and finishes?
Fiber content labelling law covers fiber content, not chemistry. That gap is exactly what OEKO-TEX Standard 100 exists to close — it tests the finished article, dyes and finishes included.
What's the single most useful thing on a clothing label?
The percentage next to each fiber. If a brand won't give one for every fiber in the garment, that's your answer.