Acid Free
 

I always see where everyone stores their fabric in "acid free" boxes or containers. My question is how do you know if the box or storage container is acid free? If it's not stated on the sale sign ect. Most of the time I see the "acid free" on boxes, do the plastic containers contain acid? I'm always needing storage containers but I'm stumped as to what is acid free, what is the acid and what does it do to the material? I'm sure back when my Mother was quilting there wasn't anything about acid free. Jeepers how many times have I said "Acid Free"? Thanks for any help on this subject I know this is the place for true to the point answers, I love this board.

If it is acid free it will say so. Acid can cause brown spots on fabrics.

It's actually a very good question. Lots of things say acid free (like some comic boards, which quilters use for folding fabric) but in reality they just have a coating - on one side only! - so they are not really acid free. And often the coating will wear off in time, so again, not truly acid free.

There is archival quality tissue paper that is used to wrap vintage clothes and the bridal shops use it to store bridal gowns after the wedding for the bride. If you want to preserve your fabric for years that would be the way to go. I don't worry about it. If the fabric is that old in my stash to get spots, then it will have spots.

i have a book that says tin foil is acid free and you can wrap things with it. I do it all the time now.

Hard plastic storage boxes do not have any acid. Soft plastic doesn't have acid either, but can outgas other chemicals that are not good for fabric.

Acid is naturally present in all wood products including cardboard boxes, cedar chests, tissue paper -- anything that contains wood or wood byproducts. "Archival quality" materials have had the acid taken out. If cardboard boxes, tissue paper, scrapbooking paper does not specifically say "archival quality", then you can expect acid. Removing the acid makes archival quality products considerably more expensive.

Cedar chests vary in how much acid they contain. Older chests tend to have dried out so there is not as much acid in them (or wood oils). Wood products in general can be treated with polyurethane, which creates a barrier to acid. Paint probably also creates a barrier against acid.