lots of people cut their patches a little larger than needed, that gives them (squaring-up) room with their blocks, it is not a biggie to have them a little big---it is easy to take away...much harder to make them grow if you cut them too small. nothing to be upset about at all, just make your 4-patches then square them up to the perfect size. but a regular square acrylic ruler i think would be a better tool for the job than a shape cutter...just my thought..