I bought mine at Target for a dollar a piece. They work well for fatquarters and sets of material. Be care ful though, if you over load them they will start to turn loose where the velcro attaches to the top. Got 4 in my closet.

I have four of them hanging in the closets in my sewing room. (we took the folding doors off the closets so they are always open and accessible.) I love the shoe holders. I use them to sort smaller collections of usually FQs. One section holds all my FQs of heart fabrics, one holds my fruit/vegetable FQs, Three sections hold my fairy frost FQs, and so forth. Very handy

Mine came with a hanger and aren't the velcro type. I got them at JoAnns using my discount coupons. I'm sure they weren't expensive.

I have seen them used by Helen Deighton - UK fabric dyer. They looked good but needed some support at the top in the middle

I have one that came with my closet organizer. I had redone my sewing closet with plenty of shelves and I use the fabric shoe holder to store my cone threads in by color.

I have both kinds and the over the rod one started to rip out on top so sewed it back togather and dont put so much weight on it now.
The over the door hanger is nice for storing videos and odd ball stuff.

I have used them. They do hang on (supposedly) with velcro. The velcro is not really strong enough if you fill each one with fat quarters, or whatever. I ended up nailing mine to the end of a shelf unit instead. LOVED it that way.

Thanks for your ideas -- I will look for the ones with hooks to go over the closet bar rather than get the velcro ones.