I was/am making placemats for my church to distribute to our local Meals on Wheels program. We need 500. Made the fronts from 7inch squares, not all of them were really square. I went to a local glass place and had them cut a 12 1/2 x 18 piece of plexiglass for a back template and a 7 inch square. $20. This was cut from the thicker sheet. We used sheets to cut the backings and it saved a lot of time. Haven't had ant irregular shapes yet but will stress accuracy.