I have some of those same shelves from IKEA. Here's something you should think about though.... Having your fabric out in the light like that may not be a good idea. It will fade, get discolored etc. IKEA makes pull out boxes that fit those niches and yes, I know, more $ but your fabric will be out of the light. I keep my fabric in my closed closet. I've inherited fabric with obvious fold, fade lines and the previous owners probably stored the fabric where light got to it.