GSM — grams per square metre — is the standard measure of fabric weight, and it's one of the most important (and most overlooked) specifications a new brand gets wrong.
What GSM Actually Tells You
GSM measures how much a square metre of fabric weighs. Higher GSM generally means thicker, heavier, more substantial fabric; lower GSM means lighter, more breathable, often more drapey fabric. Neither is "better" — the right GSM depends entirely on your product and climate target.
T-Shirt GSM Ranges
- 160–180 GSM: Lightweight, breathable — suited to hot climates and summer collections, but can feel thin or see-through in lighter colours - 180–200 GSM: The most common mid-weight range for everyday casual tees — balances durability and comfort - 220–240+ GSM: Heavyweight, premium streetwear feel — structured drape, opaque even in light colours, popular in boxy/oversized cuts
Hoodie & Sweatshirt GSM Ranges
- 280–320 GSM: Lighter hoodies, suited to warmer climates or layering pieces - 350–400+ GSM: Heavyweight fleece — the substantial, premium feel associated with high-end streetwear brands
Activewear & Performance Fabric
Activewear typically prioritizes function over weight — moisture-wicking polyester blends, four-way stretch fabrics, and compression fabrics are selected for performance properties (breathability, stretch recovery, quick-dry) rather than GSM alone, though most performance tees sit in the 140–180 GSM range for breathability.
How GSM Affects Cost
Higher GSM fabric uses more raw material, which directly increases per-unit fabric cost — heavier isn't just a feel choice, it's a budget decision that should be made deliberately, not by default.
How GSM Affects Printing
Lighter GSM fabrics can show print-through or texture distortion with heavy ink deposits (like plastisol screen print), while heavier GSM fabrics generally handle dense prints and embroidery stabilizer better without puckering.
Requesting Fabric Swatches
Never approve a fabric spec based on GSM number alone — always request a physical swatch. GSM tells you weight, but not hand-feel, drape, or how the fabric will behave after washing.
Need help specifying the right fabric for your product? OSD Apparels sources 200+ fabrics across every GSM range. Request fabric swatches and a quote.