I'm still on the fence with these.  I've never had clothing made of this material, and they seem very delicate.  They almost seem like they are made of rubber balloon material--if you could cut a balloon and make a thong out of it!  You have to smooth them down after putting them on, since they kind of roll a bit, but they do stay in place once you do that.  I have washed and worn them twice so far, and they do not show under even the tightest clothing.