My BF has some foamcore board that he purchase for mounting photos onto, and he isn't using it. So I took it to use for my fabric. It may be a solution for folding fabric and have it stiff enough to stand upright like mini bolts and be a cheaper alternative to the comic book boards. I don't know where he got it, or how much he paid for it as we have had it around for a few years. Another alternative that I didn't see mentioned in this thread is matboard. The stuff used to mat photos would be acid free, so it should be okay to put inside our fabric and not harm it. It can be purchased at Michaels or JoAnns, in large sheets, and you can use a coupon for it. I have cut matboard with my rotary cutter before, so it would be easy to cut to the size you need.