I do recommend getting the actual tool (if you don't already have it). I had made my own with a 3.5" square ruler, but the problem was it slipped and slided and was awful to try to cut. DH was holding down the ruler while I cut and it still wouldn't hold still. I bought the real one and it has these amazing grippies on the bottom where it holds so amazingly well and I don't know DH to help holding it. Definitely worth the money compared to the frustration with the DIY results
