Squat-proof leggings: how to actually test them

Almost every pair of leggings on the market claims to be squat-proof. And almost everyone has owned a pair that turned out not to be — usually discovered in the middle of a packed class, with a mirror behind you. The problem isn't always the brand lying. Opacity depends on several things that change from person to person:

• How far the fabric stretches. The same legging in the same size stretches more on one body than another. More stretch means thinner fabric.
• The colour. Light and bright colours show more than darks.
• The light. A dim bedroom forgives everything. Gym lighting and daylight forgive nothing.
• Wear and washing. Fabric can thin over time, especially with heat and fabric softener.

At FOREVER6IX, we check opacity on every legging before it goes live. But because your body and your gym aren't our test conditions, we always recommend doing your own test when a new pair arrives.

You need a full-length mirror, bright natural daylight (or the brightest light in your home) and a second mirror or your phone camera.

1. Wear your normal underwear. Ideally a pair in a contrasting colour to the leggings, so any see-through is obvious. Keep the tags on.
2. Stand with your back to the mirror, about a metre away, facing the light source.
3. Squat deep. Go as low as you would in a workout, hips below knees if you can, feet hip-width apart.
4. Look over your shoulder or take a photo with your phone held to the side. Check the seat, the backs of the thighs and the crotch.
5. Repeat in a forward fold and a wide-leg stance. These stretch the fabric in different directions.

If you can see skin, underwear lines, the colour of your underwear or the texture of your skin through the fabric, the leggings aren't opaque enough for you. Don't wash or wear them — keep the tags on and contact us.

If you're shopping in a store, you can do a quick version without changing. Put your hand inside the leg, spread your fingers and stretch the fabric gently. If you can clearly see your skin through it, it will be sheer when you squat. It's not perfect, but it rules out the worst offenders.

The most common reason leggings go sheer is that they're too small. Sizing down for extra compression stretches the fabric thinner across your seat and thighs. If opacity matters to you, go with your true size based on your waist and hip measurements in our Size Guide, and only size down if you're between sizes and prefer a firmer hold.

Signs a legging is too small: the waistband rolls, the fabric looks shiny and stretched at the seat, there are horizontal stretch lines across the thighs, or you can see the seams pulling.

For squats and deadlifts, look for full-length or 7/8 leggings in a mid-to-dark colour with a high waistband that stays put when you hinge. Brushed finishes feel soft and have a slightly denser hand-feel. The legging in the Cloud Brushed Set and the Second Skin Long Sleeve Set are good examples.

Ribbed textures, like the Ribbed Sculpt Set, add visual texture which helps hide sweat marks during a long session. Seamless styles, like the legging in the Seamless 3-Piece Set, have no seams to dig in when you're at the bottom of a squat.

For Pilates and barre, where you're bending more than loading, a flare silhouette like the Crossover Flare Legging gives you the same coverage with a more relaxed look below the knee.

Opacity can drop over time if fabric is damaged by heat or harsh washing. To protect your leggings:

• Wash cold, inside out, with similar colours.
• Skip fabric softener. It coats the fibres and breaks down stretch.
• Hang to dry. Tumble dryers are the fastest way to wear out activewear.
• Never iron.
• Avoid rough surfaces like brick walls and gym benches with Velcro, which cause pilling and thinning.

If a pair of FOREVER6IX leggings turns out to be sheer, contact us within 30 days of delivery and we'll replace or refund it. For everything else, unworn items with tags can be returned within 30 days. Please do the test before you wash or wear them to the gym.

Are black leggings always squat-proof? Not always. Dark colours hide more, but thin fabric can still turn sheer when stretched. Always do the mirror test.

Do leggings get more see-through over time? They can, especially with hot washes, tumble drying and fabric softener. Cold wash and hang dry to keep them opaque.

Should I size down in leggings? Only if you're between sizes and want more compression. Going too small stretches the fabric thinner.

While you're in front of the mirror, check the other things that make or break a legging:

• Waistband: jump up and down ten times. Does it slip or roll?
• Front seam: does it sit flat, with no camel toe?
• Length: full-length styles should reach your ankle bone; 7/8 should sit just above.
• Pockets: can you fit your phone without it bouncing?

Pass all of that and you've found a keeper. Shop the full leggings and legging sets edit or see how to style them in our gym to dinner guide.