These are a tiny bit tight, but not in a way that is uncomfortable, just in a way that looks bad when it cuts into the top of the foot. Additionally, and I should have predicted this, they are not "invisible" at all. They are made of the same material those early 2000s "clear bra straps" were made of. Are they less obvious than a bright white strip of plastic, yet. but barely. I will probably use these, but only ever with long pants that will cover the strap.