Ughhh......I was ironing pieced quilt squares. I had the iron on cotton/steam, on top of the white cloth covered board from JoAnn's, and this was on top of my Olfa mat.
I warped it! I didn't notice until tonight after work. I've tried to unwarp it (if there is such a word). It's not working for me.
Has anyone else had this issue? If so, were you able to flatten the mat again?