
Leggings make underwear lines more obvious because the outer fabric sits close to the body. The fix is not always a smaller pair. Often it is the right edge finish, rise and fabric thickness.
Under leggings, smooth underwear depends on edge finish, rise, fabric thickness and whether the pair stays in place.
A seamfree pair should sit smoothly at the edges. If the edge rolls or digs, it can show through leggings even when the fabric itself is thin.
Do a quick sit, squat and walk check. If the pair shifts straight away, it will probably keep moving during errands, training or a long day out.
For the broader range, start at women's seamless underwear or compare outfit needs with the seamfree underwear guide.
The Hipster Ultra Invisible 5 Pack is a natural match because it is built around a smooth hipster cut for low-line everyday outfits.
If cotton feel is more important than invisibility, compare with our women's cotton underwear guide.