Fabric & GSM guide for streetwear: which weight to choose

"Heavyweight" is the most used word in streetwear, and the most abused. Here's what fabric weight actually means and what to choose.

What is GSM?

GSM means grams per square metre. The higher the number, the heavier and usually thicker the fabric. It's the first spec a manufacturer will ask for.

Tip: heavier isn't always better. A 300 gsm tee feels premium in autumn and too warm in July. Match the weight to the season and the fit.

The fabrics you'll be offered

Single jersey. The fabric of almost every t-shirt. Smooth on the outside, soft loops inside.

French terry (loopback). Smooth face, small loops on the back. Breathable, holds its shape, perfect for structured hoodies and sweatpants.

Brushed fleece. French terry with the loops brushed into a fluffy inside. Warmer and cosier, but can pill more.

Rib (1x1, 2x2). Stretchy knit for necklines, cuffs and hems. Usually cotton with 3–5% elastane so it springs back.

Ripstop. A woven fabric with a grid pattern that stops tears from spreading. Perfect for cargo pants.

Waffle knit. Textured grid, popular for long sleeves and thermals.

Composition matters too

• 100% cotton: breathable, natural, takes washes and dyes beautifully. Shrinks if not pre-shrunk.
• Cotton/polyester (80/20, 60/40): less shrinkage and pilling, cheaper, slightly less premium feel.
• Organic cotton: same feel, better story; ask for certification such as GOTS.

What to put in your tech pack

1. Fabric type (e.g. loopback french terry).
2. Composition (e.g. 100% organic cotton).
3. Weight in gsm with a range (e.g. 450 gsm, 430–470 accepted).
4. Finish (pre-shrunk, enzyme wash, brushed).
5. Maximum shrinkage after washing (e.g. 3% after 3 washes at 30°C).

See how washes change fabric in the garment washes guide.