Originally Posted by sewNso
what makes it have acid?
All wood products contain acid unless treated to be acid-free. Wood products include cedar chests, paper, cardboard, tissue paper, etc. When fabric is stored for a long time in contact with wood products that are not acid-free, the acid gradually eats away at the fabric. This is why many antique quilts that were stored in cedar chests have brown spots on them where the fabric has been degraded with acid.
There are now "archival-quality" wood products available for storage, including acid-free boxes for wedding dresses, acid-free boxes for photo storage, acid-free tissue paper for putting inside the folds of quilts, etc.