I wanted a rotary cutting mat, but I didn't want to pay the price the stores want. I had an 'old' mat that was a real mess on the grid side. I cut it into a square a little bigger than one of those plastic lazy susans you use in cupboards - you can buy them at Ace cheaper than the rotary mats or maybe be lucky enough to find one at Goodwill. I glued layers of cardboard in the lazy susan to build up the center until it was as high as the 'lip' - then I glued on the old mat, non-grid side up.