benndm

I laid mine on the front sidewalk in the hot sun for the day and when I brought it in I laid it on the floor. When it cooled it was flat.

natalieg

Mine flattened out, except for one. I left them out in the 104 degree temps, then would lay them on the linoleum floor with the AC running and heavy books piled all over them, completely covering them. I did this for two days in a row. My mats are so thick that they were super hot and "melting" when I picked them up to bring them in.

ctipton

Oh good luck. I had not used mine for years and was hanging and it warped. Hubby did the heat thing.We will try it again. Good luck..

romanojg

I don't trust the measurement marks anyways; they aren't always accruate. I might use the if I need about a certain size but if I know I need a certain size then I use my ruler for measuring and the mat is just for cutting on.

Emily'sMom

I also layed my warped mat on the cement on a hot day with a board and cinder block on top and it straightened right back to normal. The mat wasn't usable before so I had nothing to lose by trying .