I have a big 24" x 72" cutting mat. I got a bargain on it and couldn't pass it up. I am so happy I bought a really big mat. It was an investment, but I have sooooo much cutting room. I also use Olfa rotary cutters, 45mm. And I use Olfa rulers, too. And it's true, each brand of ruler is a tad different from each other. I agree with Tartan about buying one of the new rulers that your rotary cutters ride in. I have cut myself too many times. I'm thinking about buying one for myself.