I bpought a flat board with slits, but quickly ran out of room also it had a tendency to want to tip over. Then I bought the ring (looks like a belt holder) that was great until I needed a ruler. I had to take off all of the ruler in front. Thst got old very fast. I did see a suggestion about putting individual snap rings on each ruler and you could hang them on the "ring" but would be able to take one off, Or hang on peg board, or on a curtain rod, ideas are endless. The large ones with the slots on this site look good but they take up too much room for me.