How to distinguish between mold and acceptable foxing?

Hello everyone,

I just picked up a lot of old paperbacks, half to a third of which unfortunately arrived with brown spots on the top. Is this a tell-tale sign of mold or an acceptable, if unwanted, kind of foxing? If it's the former, should I cut my losses with the entire lot? Thanks for any advice.

Got a photo? Personally I would rely on my nose - if the books smell mouldy, bin them. If not, take a chance.

Brown spots on old paperbacks are likely to be signs of acid damage to the paper. Chances are that the paper is also getting brittle. Like >2 abbottthomas:, I would use my nose.

I have noticed that books using paper from the U.K. is a little more prone to foxing than U.S.-sourced paper. It could be different processes, water, or fiber sources.

Foxing is also more common on older books (say before 1965) than newer ones.

James

Using you nose is fine if 1) you don't have a compromised olfactory sense, and; 2) you're not sensitive to mold. For me, it's hard for me to detect odors, and I break out into hives at even the sight of blue cheese.

What you're describing sounds more like what MarthaJeanne said in #3.

My advice: Take no chances. Put the book into a Zip-Lock bag, squeeze the air out of it and make sure it's sealed. Then place it in the back of the freezer for a week or two. It depends on how often you open it (the freezer) afterward. The freeze should kill off the mold. When you remove it from the freezer, place the still-sealed bag on a cooling rack and wait until the book is at ambient temperature. Before you open the bag, wipe it off with a dry dishtowel or paper towels. If, over time, the discoloration continues, it's definitely foxing.

Freezing will not kill mold. I simply makes it go dormant. http://cool.conservation-us.org/byauth/nyberg/spore.html

Hi All,

Would you be able to tell me more about foxing vs. other damage? I recently acquired this book and am not sure if this is foxing or mold that might spread to my other books. It looks like common foxing; however, surprised to see the discoloration on the DJ edges. I appreciate your help. Pictures below:

Not mold.