Dingle - the mats were easy to cut using a paring knife. Then I used craft scissors to round the three corners that weren't rounded by manufacturer. I also vacuumed them before I cut them as the friend who picked them up for me thought they shed. I didn't find that but maybe that's because I vacuumed them as soon as I took them out of the bag.
I think they will work fine. They do hold the heat when pressing and make a nice press.