Ballet flats are derived from soft ballet slippers, having very thin heels or the appearances of no heel at all. The style often features a ribbon-style binding around these flats' low top areas. Some ballet flats are open toed. The essence of the ballet flat has been on since at least the 15th or 16th century. They're worn primarily by women, although men may wear them too. They went out of fashion during the 18th and 19th century, but took off again after Audrey Hepburn wore the shoes in 1957's Funny Face.