You can have a square of plexiglass cut at a local glass or hardware store for about $7 or less. I have done this a couple of times. You won't have any lines on it but you can always put them on with a Sharpie. If you are just wanting to fussy cut, this would be ideal for you. Cheaper than the fussy cut rulers out there and very convenient! I had one cut when I had 100 HST blocks to cut down to 2 1/2" square. Cost me 3 bucks and well worth the price. I just took a sharpie and drew the diagonal line on it so I could place it correctly on my HST blocks.