Briefs under tight trousers and how to avoid edges

Short answer: A visible line comes from elastic that is thicker than the fabric around it. The fix is a laser cut edge, a different cut or trousers in a denser fabric.

Why the edge shows

Under tight trousers the fabric lies close to the body and shows whatever is underneath. Elastic at the leg opening is thicker than the rest of the briefs and presses slightly into the skin. That creates a small ridge on each side, and that ridge is what shows up as a line through your trousers.

Laser cut edges

A laser cut edge has no elastic and no seam. The fabric is cut so it does not fray, and the edge lies flat against the skin without forming a line. It is the most direct fix, because the cause of the line is gone. Many people choose this style for tight trousers and fitted skirts. See bamboo briefs.

The cut is the other route

When the leg opening runs up towards the hip at an angle, it follows the natural line of the leg and shows less. An edge running straight across the back of the thigh forms a clear line instead. That is why a tai shows less than a hipster, even in the same fabric. The cut can do a lot on its own.

Seamless styles

Seamless briefs are knitted in one piece without side seams. They have no edges or seams that can show, because nothing is thicker than the rest of the fabric. They follow the body closely and lie smoothly even under thin trousers, which makes them an easy choice for fitted outfits. See bamboo underwear for women.

The right size

Briefs that are too small dig in and create a bulge above the edge, which is easy to see. Briefs that are too big can fold or bunch under trousers. The right size lies smoothly without pressing. A larger size will not remove the line from a thick edge, though. Only a thinner edge does that.

The trousers matter too

Thin, light trousers show everything, even an edge you can hardly feel. Densely woven trousers hide edges, whichever briefs you wear. Jeans and heavier fabrics rarely cause trouble, while leggings, thin suit trousers and light summer trousers are where the edge of your briefs matters most.

Colour counts

Briefs in a shade close to your own skin tone show less through light trousers than white or black ones. White can shine through a light fabric, and black is clearly visible under white. For light and thin trousers, a nude shade is the safest choice, both for the edge and for the briefs themselves.

Check in the mirror

Put the trousers on and look at yourself from the side and from behind in good light. Walk a few steps and sit down, because an edge can lie flat when you stand still and show when you move. Then you know which combination of briefs and trousers works, and you can reach for it again.

Find your measurements

To get both cut and size right, start from your own measurements rather than a size from another brand. Measure around your hips and compare with the size chart. The measurements and an overview of the different cuts are in our guide to briefs and underwear.