Hoodie & T-shirt GSM guide: what fabric weight really tells you

What GSM is

GSM — grams per square metre — is the weight of one square metre of fabric. It is the single most useful number for communicating how substantial a garment should feel, because 'premium heavy cotton' means nothing in a specification and '240 GSM combed cotton jersey' means exactly one thing.

GSM describes weight, not quality. A 180 GSM tee in long-staple combed cotton can feel far better than a rough 240 GSM one. Weight, fibre, spinning and finishing together make the hand feel — but GSM is the part you can specify precisely.

T-shirt weights: 160 to 240+ GSM

• 160–180 GSM — lightweight: soft drape, cooler to wear, common for promotional tees and summer basics. Light colours can be slightly translucent.
• 180–200 GSM — the retail standard: the balance most brands choose for everyday tees; opaque, durable, takes print well.
• 200–240 GSM — heavyweight: boxy, structured drops and streetwear staples; holds an oversized silhouette instead of clinging.
• 240 GSM+ — ultra-heavy: a deliberate design statement; stiff at first, breaks in with washing, ages well.

Fleece weights: 280 to 450+ GSM

Hoodie and sweatshirt fabrics are measured the same way but live in a different range, because fleece is a three-thread or loopback construction with a brushed or looped back:

• 280–320 GSM — lightweight fleece: hoodies for layering and warm climates; softer drape, lower perceived 'premium' weight.
• 320–380 GSM — mid/heavyweight: the standard for quality streetwear hoodies; structured hood, substantial cuffs.
• 400–450 GSM+ — heavyweight: the boxy, stand-up-on-its-own hoodie; strongest perceived value, warmest, and the most fabric cost per garment.

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How GSM changes print, drape and cost

Printability: heavier, denser knits give a flatter, more stable print surface; very light jerseys can show fibrillation through DTG prints. Embroidery sits best on heavier fabric — on light tees it needs backing and restraint.

Drape: weight is the main lever between a garment that flows and one that holds a silhouette. Oversized fits in light fabric look deflated; the same pattern at 240 GSM looks intentional.

Cost: fabric is bought by weight, so GSM moves cost twice — more grams per garment, and more shipping weight per carton. A 450 GSM hoodie simply contains roughly 40% more fibre than a 320 GSM one; no factory can quote around that.

Specifying and verifying GSM

Specify GSM with the composition and construction — '380 GSM, 80/20 cotton-polyester brushed-back fleece' — and expect a manufacturing tolerance of a few percent between dye lots; a serious factory checks inbound fabric weight with a GSM cutter and shows you the number.

When you approve a sample, weigh it. A kitchen scale and the garment's measured area get you close enough to catch a substitution. At LOMERAQ, inbound fabric inspection includes GSM, shade and shrinkage checks against the approved specification.

Choosing by market and season

Match weight to how and where the garment is worn: promotional and event tees live happily at 160–180 GSM; retail basics at 180–200; streetwear tees at 200–240. For hoodies, northern-European autumn/winter retail expects 350 GSM and up, while a gym-bag layering hoodie is better at 300. When in doubt, order a sample in two weights — fabric decisions made by hand beat fabric decisions made by adjective.