Many people try to make their own, but it isn't worth it. Buy these. They are from Wishblade, fairly inexpensive & worth the money. It's worth having a couple extra around the house. I'm so glad they come in a 2-pack & that they come with extra O-rings. I've never lost an O-ring, but I think many people do misplace theirs. I get extra life out of my mats by cleaning them with a baby wipe & then spraying it with Krylon Easy Tack after it's dry.
If you are using your wishblade to cut a lot I recommend having 3 mats. 1 for cutting dark cardstock, 1 for cutting light cardstock, and 1 for the thinner patterned paper. Oh and if you have the pink wishblde you don't need the o-ring!
The product itself is amazing. The adhesive is perfect....it holds the paper in place without making it difficult to remove. The huge downside? They don't last too long. Xyron had told me they are meant to last 6 months, but I have yet to get mine to go even half that long. Because ANY Wishblade product is impossible to find locally, I use a spray adhesive to make the mats go further, however, these things collect lint, dirt, bits of paper, and get grubby easily (especially when the original adhesive no longer wants to hold the protective covers).
Spray adhesive works, but can be difficult when trying to remove paper. Of course, then you add on the fact it is being sprayed and it can leave gritty residue on other things since it becomes airborne..... UGH. Just UGH.