GSM Explained: Choosing the Right Fabric Weight
GSM — grams per square metre — is the single most useful number for describing how a garment will feel. It measures fabric weight, not quality, but it is the fastest way to communicate the difference between a thin promo tee and a structured heavyweight blank. Here is how to read it.
By Raj Rahman, Founder & Managing Director
What GSM actually measures
GSM is the weight of one square metre of fabric. A higher number means a denser, heavier, usually more opaque and structured fabric; a lower number means lighter, softer, and more breathable. It does not, on its own, tell you about fibre quality, construction, or durability — a well-made 180 GSM tee can outlast a poorly made 240 GSM one.
A weight-by-weight guide for knits
- 130–150 GSM — lightweight promo and fashion tees: airy, drapey, budget-friendly for giveaways and layering
- 160–190 GSM — the retail standard: the classic everyday t-shirt weight, balanced and versatile
- 200–230 GSM — premium tees: substantial, holds shape, a quality retail feel
- 240–280 GSM — heavyweight and boxy streetwear blanks: structured, opaque, that "expensive" hand-feel
- 280–320+ GSM — super-heavy tees and lighter sweats: maximum structure for premium streetwear
- 300–500+ GSM (fleece/terry) — hoodies and sweatshirts, from lightweight to ultra-heavy
How to choose for your product
Match the weight to the positioning. Promotional and event apparel usually lives at 140–180 GSM to hit a price point. Retail basics sit at 180–220 GSM. Premium and heavyweight streetwear starts around 240 GSM and climbs from there.
Remember that heavier is not automatically better — it is warmer, costs more in fabric, and drapes differently. The right answer depends on climate, use, and brand feel.
If you are chasing the 320+ GSM end of this range specifically, the block, neck and finish choices that go with it are on our heavyweight t-shirt page.
Always approve a physical sample
GSM gets you close, but knit construction, finishing, and fibre all change how a given weight feels in the hand. The reliable move is to approve a physical sample in your exact fabric before committing to bulk — every order we run is locked against that approved sample.
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