What is GSM?
GSM stands for grams per square metre — the weight of one square metre of fabric. Higher GSM usually means a denser, heavier, more opaque fabric; lower GSM feels lighter and more breathable.
But GSM alone doesn’t define quality. A 180 GSM combed ring-spun jersey can feel far more premium than a 220 GSM open-end yarn fabric.
Always specify GSM after washing and finishing, with a tolerance (typically ±5%).
Recommended ranges
Typical weight ranges by product (placeholder reference values — confirm with your own fabric tests):
| Product | Light | Mid | Heavy | Notes |
|---|---|---|---|---|
| T-shirts | 140–160 | 180–200 | 220–300 | Lightweight summer / fashion tees vs heavyweight boxy streetwear tees. |
| Hoodies & sweats | 240–280 | 300–350 | 380–500 | Mid-weight for layering; 400+ for premium heavyweight drops. |
| Polos | 180–200 | 200–230 | 240–260 | Piqué weight drives structure and collar stability. |
| Activewear | 120–160 | 170–220 | 230–300 | Leggings need higher weight for squat-proof opacity. |
| Workwear | 200–240 | 250–300 | 300–400+ | Wovens are often specified in oz/yd² instead of GSM. |
Beyond weight
- Yarn — combed ring-spun vs open-end changes softness and pilling.
- Knit structure — jersey, rib, piqué, interlock and terry behave differently at the same weight.
- Finishing — brushing, enzyme wash and garment dye change hand-feel and final GSM.
- Climate & season — your customers’ market matters as much as your aesthetic.
How to verify GSM
Use a GSM round cutter (100 cm² sample) and a precision scale: weight in grams × 100 = GSM. Test at least three points across the fabric width, before and after washing.
We include GSM test results in every fabric approval pack. (Placeholder claim — adapt to your process.)
Quick checklist
- Define the product’s season, market and price point.
- Pick a GSM range from the table, then shortlist 2–3 fabrics.
- Request swatches and wash tests before sampling.
- Lock GSM ± tolerance in your tech pack.
Not sure which weight fits your line?
Send us your product brief and we’ll ship a free swatch set (placeholder offer).
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