I was able to pick up lots of plain brown, rather thin cardboard that are exactly the same size. I think they will hold fabric okay. My idea is to fold the fabric around the cardboard the way many of you do with the plastic holders that can be purchased. My question is how do I know whether they would be safe for long-term storage. Do you think that the fabric will change in color over time or disintegrate? The are used to store paper for long term storage, so do you think that makes them safe to use?

I'd be a little concerned that the cardboard would mark your fabric ... I suspect that it isn't acid-free. If it's a temporary thing, not likely a big issue. But if you're worried it might disintegrate, it sounds like they may be on the cardboard for a while.

They use cardboard bolts at the stores? So I would think if you're constantly rotating the fabrics (using it up, buying more) that you'd be ok?

NO...that cardboard is probably NOT acid free...and if it is like shirt cardboard it won't hold up to the weight of the fabric!

IF you think you have to use this then wrap it in freezer paper first to protect your fabric from the acid in it....

This doesn't really answer your question but I heard recently on the board that comic book cardboard is acid free.
I'm thinking of doing the same thing with my stash.

yep, I even found the right size,, it is actually the LIFE magazine size that I need to fit my shelves..but wow..still costly when you consider the size of my stash....and the fact that I would have to hire help in to help me...or give up a year of my life to complete the job..ehhehe