Quite often, the self-healing mats tend to warp, particularly when exposed to heat. And once warped, they become almost useless. This is why flattening them is essential. Good news – you can do that with just a few simple tricks. One of the best ways to do that is to apply heat and pressure. For this, you need an iron. You’ll also need a cloth to protect the surface of the mat. Thirdly, you’ll need a wooden plank to distribute the pressure on the mat evenly. And finally, some heavy objects to keep the mat flat. You start off by heating the iron and ironing the mat. Once there’s enough heat on the mat, place the heavy objects on it to retain the rectified warped area.