I have a pear-shaped body, I weigh 180 Lb, so I bought the largest size, and It fit well ... until it started to get eaten by my butt XD. I think I would need to spray that area or something?. Despite this, it really is a very light weight pantie, totally unseen. Just a clarification, IT IS NOT MADE OF COTTON COMPLETELY, only the bridge in the crotch area. And I that wanted some fresh panties for the summer! Anyway, I'll keep them to wear with leggings or formal work clothes.