Short version: For leggings, aim for 230–300 GSM in a 75–80% nylon / 20–25% spandex (or 94/6 seamless) blend with 4-way stretch. Heavier = more squat-proof and sculpting; lighter = more breathable.
What does GSM mean?
GSM = grams per square metre, the weight of the fabric. It's the single biggest lever for how activewear feels and performs. Light fabrics breathe and drape; heavy fabrics compress, sculpt and hide.
GSM by product
- Leggings: 230–300 GSM. Below ~220 risks see-through; 260–300 is the premium "buttery, squat-proof" zone.
- Sports bras: 220–280 GSM depending on support.
- Tops & tanks: 180–240 GSM for breathability.
- Seamless sets: typically 280–300 GSM, 94/6 polyamide-elastane.
Composition: nylon vs polyester, and spandex
Nylon (polyamide) is softer, more durable and has that "buttery" handfeel — the premium choice for leggings and sets. Polyester is cheaper, dries fast and takes sublimation print well — common for training tees and printed styles. Spandex (elastane) at 6–25% gives the stretch and recovery. More spandex = more compression and snap-back.
What makes leggings "squat-proof"?
Three things: enough GSM (260+), a tight knit, and the right fabric tension at the seat. Thin or low-tension fabric goes sheer when stretched. A good factory squat-tests every fit sample under bright light — always ask for this.
Finishes that sell
- Brushed / "naked feel": peach-skin softness, hugely popular.
- Ribbed: texture + gentle compression, on-trend for sets.
- Matte vs shine: matte reads premium; shine reads sport.
- Recycled (GRS): recycled nylon/polyester for sustainability claims.
FAQ
What GSM is best for leggings?
230–300 GSM. 260–300 for premium squat-proof compression; ~230 for lighter, breathable styles.
What's the best fabric blend for activewear?
75–80% nylon / 20–25% spandex for cut-and-sew, or 94/6 polyamide-elastane for seamless. Polyester blends for printed training wear.