My shelves are 24 inches deep in my sewing closet. I made them this deep on purpose. My fabrics are folded as they come off the bolt and approximately the same width of 9 inches. Then they are stacked by color family. I posted pictures earlier this year of my closet. The post was called My patchwork parlor. \
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This was the only way I could come up with to accommodate all of my stash and still make some sort of sense out of it all. I hope this helps you.