The most comfortable and smoothest lines under your clothes.  I ride a bicycle and have problems with irritation in the seat area.  These have no seams in places that rub or bind.  They are cotton with some spandex, and they have a high rise.  However , you can push them down and they are so thin you do not notice them.

best bike riding underwear I have ever found.  Good for wearing around the house, too, they can pass as shorts if you have to open the door for a second.  No panty lines to be seen or felt.  The long ones do sometimes ride up inside my shorts when I put them on, but I smooth them down and they stay ok.  they get wrinkly along the leg part from being pushed up, perhaps they are only made for skirts.  I like them for my arthritic hip, which likes to stay warm.

 I do not think the little crotch gusset (which is shaped in a strange ovaloid shape with flat seams )  is made of anything different.  I prefer pure cotton, but have had no problems with these.