Coroplast for fabric organization may be a mistake!
I want to organize my stash and I read somewhere that the Coroplast (plastic board) was acid free. If you go to the Coroplast website there is one type of Coroplast that is archival quality. The sign maker I talked to said he would never buy that type of material because it is not UV resistant. He suggested I try calling someone who does picture framing to find Coroplast-Archival which is what they call the chemically inert type of Coroplast on their own website.
Chemicals are very unpredictable. I recently opened one of those storage bags that I had used to put a comforter in. (This was a store bought comforter from about 3 years ago.) It was in a "Space Bag." One of those that you vacuum the air out to store it without taking so much room. The smell was unbearable.
I have also put a fat quarter bundle of Christmas fabrics into a gallon size Zip-loc bag, to transport it while looking for other fabrics. I set the project aside and didn't take the fabric out of the zip-loc bag. When I opened the bag about a year later, the chemical smell was awful. The chemicals were on the fabric, not the bag. Not letting that fabric breath was a mistake.
I try to protect my investment as much as possible. If most of us did the math, on what it would cost us to replace your stash, most of us would have a heart attack.
I protect my fabric from light too. I have a lot of scrapbooking in my past and I know how much damage time and light can do. I store my scrapbooks in white cotton pillow cases on the shelf. I always made sure my stuff was acid free and archival quality. It should have minimal fading, but I guess you never know whether each thing really is archival quality or not. They started to fade on the bookshelf so I researched and found the pillow case idea.
I have looked all over the web, and there are very few reliable/knowledgeable sources of information on how to store your fabric. Most of the information out there is from well-meaning, but uninformed bloggers. There isn't much information on safe fabric storage in published books either. Remember, "Just because it is in a book, that doesn't make it true." You really have to do your own research and check the credentials of your sources of information.