When the corners of a rug curl up, not only is it very dangerous but it’s unsightly too. To fix this, first bend the corners the opposite way and lay flat. Next, with a warm iron press down for a few minutes, then place a very heavy book or two on top for about 2 hours. The heat will have made the rug’s fibers more flexible so they will bend back into shape and the book’s weight will help the rug to stay flat.