Non see-through gym leggings: what fabric to look for (squat-proof)
It is the number one fear when buying gym leggings: that they go see-through right in the squat, the lunge or the stretch. The good news is that it is not a matter of luck. There are concrete details in the spec sheet that tell you whether a pair of leggings will be opaque or not.
In this article
Why some leggings go see-through
When you squat, the fabric over your glutes stretches a lot. If the fabric is thin or has low density, the threads separate and let light through. The most common causes are:
- Low fabric weight: the fabric is too light.
- Too little elastane: the fabric stretches but does not recover, and "opens up".
- Size too small: the leggings are already stretched before you move. See how to choose your size.
- Badly placed seams in the central area that open up when stretched.
The 4 details to check
| Detail | What to look for |
|---|---|
| Fabric weight (GSM) | Around 230 GSM or more: dense and opaque without being hot. |
| Composition | Nylon/polyamide with 20-25% spandex/elastane. |
| Construction | Flat (flatlock) seams or seamless knit. |
| Squat-proof label | Shows the brand designed them with squats in mind. |
The squat-proof test at home (30 seconds)
- Put the leggings on and stand with your back to a mirror in good light (natural light is best).
- Do a deep squat and hold it for 3 seconds.
- Look over your shoulder: if you can see skin or underwear, they are not opaque.
- Repeat with a lunge and a forward bend.
Does colour matter?
Yes, a little. Dark colours like black hide more, and light shades reveal thin fabric sooner. But a good fabric is opaque in any colour: that is why our Sculpt leggings also come in grey, petrol green and lavender.
Other benefits of a good gym fabric
A quality technical fabric is not just opaque: it also breathes, dries quickly and recovers its shape after every wash. To keep it that way, follow our leggings care tips.
Frequently asked questions
What does squat-proof mean?
That the leggings stay opaque when you do a deep squat, the moment the fabric stretches the most.
What is fabric weight or GSM?
Grams per square metre of fabric. The higher it is, the denser the fabric. For gym leggings, around 230 GSM is a great balance between opacity and breathability.
Do leggings become see-through after washing?
Hot water and tumble dryers damage elastane. Wash cold and air-dry to keep them opaque.