A long time ago, I folded all the fabrics onto the hard plastic boards only to discover the method didn't work for me. So all the fabrics un-folded off the boards and then ruler folded with a 6.5 inch ruler. I can fit 8 stacks across each closet shelf and sort by color or theme. The boards didn't work for larger cuts of yardage.
The closet shelves are 16 inch deep and the folded fabrics are approx 11.5 so fit quite well.