I found that the thick cutting mat is way stickier than the thin cutting mat. What type of paper were you cutting? I've started using the thick cutting mats exclusively. They are usually really sticky for me for the first cut or so.. but after that the stickiness is just right and I seem to get alot more life out of them over the thin cutting mats. Here is a neat trick I found- use an uphostery grade lint roller- it picks up all the extra paper that sticks really easily, and the mat stays sticky. I run mine over my mat after each cut and it picks up all the little leftover pieces, lint, oils etc and the mat stays nice and sticky
