Every roll of fabric and every garment has a content label. "100% cotton." "60/40 cotton-poly." "95% polyester, 5% spandex." Those numbers aren't random — they tell you exactly how that fabric is going to behave. Here's how to decode them.
100% cotton
The OG. Cotton breathes, absorbs moisture, feels natural on skin, and takes dye like a champ. It's biodegradable and gets softer with every wash.
The downsides: it shrinks (3-8% on first wash depending on the weave), wrinkles easily, can pill over time, and doesn't dry as fast as synthetics.
Best for: tees, hoodies, jeans, towels, bedding — anything where comfort and breathability matter most.
100% polyester
Polyester is a plastic-based fiber. It doesn't shrink, doesn't wrinkle, dries fast, and holds color well even after tons of washes. It's also way cheaper to produce than cotton.
The downsides: it doesn't breathe as well, traps odors more easily, and has that "synthetic" feel that some people don't love. Also not great for the environment — it's essentially plastic.
Best for: athletic wear, sublimation printing, outdoor gear, anything that needs to be moisture-wicking or quick-dry.
Cotton/poly blends
Most common blend you'll see is 80/20 or 60/40 cotton to polyester. The idea is to get the best of both: the natural feel and breathability of cotton with the durability and shrink resistance of polyester.
More cotton = softer, more natural feel. More polyester = more durable, less shrinkage, holds shape better.
The classic 50/50 blend is what most basic printed tees use. It's cheap, consistent, and easy to print on. But it won't feel premium.
What about spandex/elastane?
When you see "5% spandex" or "3% elastane" (same thing, different name), that's what gives fabric its stretch recovery. Without it, a knit fabric will stretch out and stay stretched. The spandex is what pulls it back into shape.
2-5% is standard for most stretch garments. Leggings and activewear might go up to 8-15%. You don't need a lot — a little goes a long way.
Other fibers you'll see
- Rayon/Viscose: semi-synthetic, made from wood pulp. Drapes beautifully, feels silky, but shrinks aggressively and wrinkles easy. Great for flowy tops and dresses.
- Tencel/Lyocell: like rayon's eco-friendly cousin. Similar drape and softness, but more sustainable production and less shrinkage. We carry a lot of Tencel blends.
- Modal: another wood-pulp fiber. Super soft, resists shrinkage better than rayon, holds color well. Popular for underwear and loungewear.
- Bamboo: usually processed into rayon (so "bamboo rayon"). Naturally antibacterial, super soft, breathes well. Great for basics and activewear.
- Nylon: strong, lightweight, slightly stretchy on its own. Common in activewear, outerwear, and swimwear.
How to use this when buying fabric
Know your end product first. If you're making premium tees for a streetwear brand, you probably want 100% cotton at a heavy weight. If you're making joggers that need to hold their shape through a hundred washes, a cotton/poly blend with some spandex makes more sense.
The content label tells you the starting point. The GSM (weight) and the knit or weave structure tell you the rest. Put those three together and you can predict exactly how a fabric will look, feel, and perform before you sew a single stitch.