Are these the cardboard things a fabric bolt is found on? Most of them are not acid free so you can get "ghosting" where you can actually see where the fabric was exposed to the acids outgassing from the cardboard. I was at a LQS and the woman in front of me was purchasing a bolt. The fabric was being unwrapped and you could see the ghosting get more intense the closer to the inside of the bolt they got. She opted not to buy it because it was damaged. I alway am interested in finding ways to neaten up my fabric but realize manufacturers expect product to be off those cores in less than a year (usually) so they don't worry too much about preserving their product. Maybe an acid free foamcore board?