You will often see a number like 250 GSM or 430 GSM on a T-shirt. Here is what it means and why it matters.
What does GSM mean?
GSM stands for grams per square metre. It measures how much one square metre of fabric weighs. The higher the number, the heavier and usually thicker the fabric.
What counts as a heavyweight T-shirt?
There is no single industry standard, but as a rough guide:
- Lightweight: under about 150 GSM. Thin and airy.
- Midweight: roughly 150 to 200 GSM. The typical everyday tee.
- Heavyweight: roughly 200 GSM and above. Thicker, more structured and more opaque.
Weftelle pieces range from 250 GSM to 430 GSM, so they sit firmly in heavyweight territory.
How does fabric weight change a tee?
- Structure: heavier fabric holds its shape and hangs away from the body.
- Drape: it falls cleanly instead of clinging.
- Opacity: thicker fabric is less see-through.
- Warmth: heavier cotton is warmer, which suits cooler days and indoor spaces.
The trade-off is breathability. Heavyweight cotton is ideal for everyday wear and after the game, while lighter technical fabrics are better while you play.
How to care for heavyweight cotton
- Wash cold on a gentle cycle, inside out, to protect prints and finishes.
- Tumble dry low or hang dry to limit shrinkage.
- Avoid bleach, and do not iron directly over prints.
Find your weight
Compare our styles: the 250 GSM Rally Tee, the 400 GSM Kitchen Boxy Tee and the 430 GSM Baseline Heavyweight Tee. Or shop everything.