I just got a few very old (18th century) books that have some pretty significant foxing on them. Because I apparently have some sort of compulsive disorder, I want to take a shot at cleaning them up a bit.

I know that foxing has been discussed here before and that some of you have had success getting rid of it with an eraser. My issue, though, is that the paper is much thicker and rougher than any type of paper that you'd see in a book today, so I'm not sure how well that would work. I'm leaning toward trying some sort of chemical solution.

I've seen dozens of different suggestions on the internet, but nothing really sounds like a definitive answer. Have any of you ever attempted to clean up foxing on paper that old before?


Founding member
I don't know that foxing is "removable," really. I've never seen an effective technique (outside of bleaching) to remove it.

You can stabilize the paper with Bookeeper, a magnesium oxide "de-acidification" solution that neutralizes the acids in the paper. But that's used mainly on post 1850 wood pulp paper. Paper made before 1850 is mostly rag (cotton), and it isn't as susceptible to browning from acids.

That isn't much help, but it'a all I've got.
I think MJP is right. As I understand it, foxing is due to impurities in wood pulp which react with humidity. I think stabilising by de-acidifying is the best that can be done. I would be wary of bleaching as that would also affect the ink. Sadly, I don't think there is any solution but I'd be happy if someone else knew better.
Finding a way to stop it would probably be about the best that you could hope for. Are the books valuable? If not, it may be worth trying, but there are book conservation groups that could give you a quick Y or N about if it is even possible.
Are the books valuable?
They would be if they didn't have all of this foxing. :)

But I bought them for a small fraction of what they normally go for, and I have no interest in cleaning them up for the purpose of reselling or anything. I just like salvaging old beat-up things and trying to make them better.

I've done quite a bit of internet research on the topic, and unfortunately there is no easy answer. But there is bookbinder in Canada who seems to have cracked the code. He says that the formula isn't marketable because of inconsistencies in spore type, paper type, etc., but that it is possible. Some of his examples are pretty impressive.

For what it's worth, he also mentioned that the term 'foxing' comes from (F)errous (ox)ide, which is apparently the chemical in paper that attract spores and causes this to happen. So at least I learned something.

foxing pre-treatment.jpg foxing post-treatment.jpg


old and in the way
Interesting... I never heard that about ferrous oxide attracting spores. Does that mean that foxing is a type of mold or fungus? I always thought it was caused by a combination of acidity, moisture and iron (ferrous oxide) particles in the paper (creating sort of a paper rust), and I've never had any success trying to get rid of it.

Bleaching would damage the paper, but I wonder if hydrogen peroxide would do anything to help. I'm sure someone has probably tried that, but maybe if you have a throwaway foxed paperback, you could experiment a little.

An unrelated PS: I'm very proud to be one of the Unholy Ones. Whatever it means, it sounds like something I would aspire to.
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I believe that it's fungal, but my thought is that it's possible that the fungi are oxidizing the ferrous oxide to ferric oxide (there are many microbial reduction/oxidation processes that go on all around us); hence the rust color of much foxing. But apparently, foxing isn't necessarily always that reddish-brown color we commonly see. I guess the term came from the color of a fox, but there seems to be enough uncertainty in the available on-line resources that I get the sense it is still something of a mystery.
An unrelated PS: I'm very proud to be one of the Unholy Ones. Whatever it means, it sounds like something I would aspire to.

Amen. :rolleyes:


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there is bookbinder in Canada who seems to have cracked the code. He says that the formula isn't marketable...

What I've read in the past leads me to believe it is fungal, which is why it's so difficult to conquer. I question ferrous oxide being the root of "foxing" though, since the term has been around for a long time. And how much ferrous oxide is in rag paper? Maybe a lot, what do I know. Just sounds like something that would be more prevalent in wood pulp paper.