I used 2" squares. I sold most of them - some were gifts and I think I have a couple of them floating around here. The last few I made were mounted on stretcher frames (like a painters canvas) because it showed off the pattern better.
At that time, I was using the reverse fuzzy side of a flannel tablecloth, tacked to the wall, as a design surface. I used a Sharpie marker to make a 2" grid on it.