Some books went wavy

Anyone else have the experience of s few Folios getting wavy pages when humidity goes up? We typically leave our humidity at 45% - but last night it spiked to 60 due to temp changes and now a few folios are wavy. I noticed that it tends to go away in a couple days after humidity returns to normal. Any others experience the same?

Not the pages, but I have a few whose boards have warped badly and it doesn't go away. My house has good climate control, so it is not due to the humidity or temperature.

Yes, this happens occasionally to some of my books. It is, as you say, the direct result of a rise in air humidity. And, as in your case, they return to normal very quickly when the humidity returns to normal. I have had secondhand books arrive in the post in that condition, but after a few days they have recovered and have remained ok. I rescued a couiple of folios from an unheated room over my late father's garage once, which took a while to recover, but even they are fine now. A similar thing happens if you take out a book during a flight, except that that, I think, is due to an excessively dry atmosphere. The only way to avoid it at home is to keep all your books under properly measured climate control, but all I can say is that none of my books, as far as I can tell, has been permanently damaged by the occasional fluctuation. For example, I haven't noticed the dreaded foxing on any of my books that didn't have it before. Frequent, excessive and extreme variations in humidity, however, would definitely be something to concern me.

Our humidity fluctuates seasonally between about 38 and 55. We had. Day that got up to 60 or so and that made a few text blocks go wavy. But only a few. I too have bought ones wavy that have gone back to normal. I've never seen a foxed folio. I think the slipcase a help things from being too extreme.

It is interesting, though, that I never have wavy pages or warped boards in my less expensive trade editions, none of which have slipcases.

I notice it in most of my Oxford publications that hard hard backs on acid free archival paper, then just goes away... I will say that one nice things about enbooks is that "neither moth nor rust destroy"

Yes, it happened (just slightly) to my one and only Arion Press book.

I suspect that if the book remains at a high humidity for a lengthy period, the waviness will not go away, but if you catch it early, it will return to normal. Mine sit at 35 - 55 RH, occasionally a bit higher on a cold winter night, and I haven't had any waviness problems (other than the odd book that arrived wavy and has remained so).

Edit: I had an Easton Press volume that arrived last week that had quite a bit of waviness. The room was at about 50% RH to start with. I fanned the page block and put the book above and to the side of my dehumidifier and ran it for about 3 hours (possibly a bit less), with dry air being blown close to (but not directly at) the fanned page block. The room RH dropped to 41, and the page waviness completely disappeared. I'd have taken before/after pics, but I didn't really expect such a significant change in such a short time. Presumably the book picked up a slight bit of extra humidity in the post. I guess it would have fixed itself naturally, it would have just taken a bit longer than using the dehumidifier on it.

This worries me.In Mauritius,there have been massive downpours recently,and I fear my books got wavy.
The thing is...I'll only be back home in late June.

:/