I have a very reliable method for cutting large squares. But it requires one of these.
http://www.amazon.com/Starrett-FS-24-Professional-Framing-Square/dp/B002BWKO3S# And if you want to make a larger than 24" square you'll need another steel straightedge of 36" or whatever length you are aiming for. Once you cut a right angle, there are a few ways you can finish cutting the square. I bisect the first 90deg corner I just cut, folding one of the square's diagonal creases. Then unfold. Then I fold the first 90deg corner to a point on the previous crease. This makes the second diagonal crease of the square. Now I don't unfold, I cut around the edges of the triangle. Then you have your square. PS it's important to use steel rulers and sharp blades! Seth WWW.FRIEDMANORIGAMI.COM
