Manufacturing
Choosing Fabric GSM for Activewear
GSM is the number most first-time brands under-specify. Here are the weights that actually work per garment type.
GSM stands for grams per square metre. It is the most useful single number for describing fabric weight, and leaving it out of a tech pack guarantees a sample you did not expect.
Typical weights by garment
- Performance tee: 130-160 GSM
- Cotton tee: 160-200 GSM
- Long sleeve base layer: 180-220 GSM
- Leggings and compression: 240-300 GSM
- Mid-weight hoodie: 280-330 GSM
- Heavyweight hoodie: 350-450 GSM
What GSM changes
Higher GSM improves opacity, structure and perceived quality, but adds cost, warmth and shipping weight. Lower GSM improves breathability and drape, at the risk of transparency in light colours.
The opacity test
For leggings, always request a squat test photo on the actual bulk fabric in the lightest colourway. This is where cheap programmes fail publicly.
Specifying GSM correctly
State the target GSM plus an acceptable tolerance, usually plus or minus 5%, and confirm whether the figure is finished weight after dyeing rather than greige weight.
Not sure which fabric weight suits your product? Request a quote at beltasports.com with your garment type and use case, and Belta Sports will recommend GSM options and send fabric swatches before sampling.
Related reading
Planning a brand from scratch? Start with our pillar guide: How to Start a Sportswear Brand in 2027.
Ordering for a team or club specifically? See our guide to custom team jersey MOQ, lead times and costs.
About the author
Ayesha Rahman
Product Development Lead, Belta Sports
Ayesha works with emerging activewear labels on fit, fabric selection and production readiness, and has taken more than eighty first-time brands through their debut run.