Book Warping?

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Book Warping?

1-Ophidian-
Mar 13, 2021, 8:08 pm

I've been having some issues over the last month or so with books warping. I've had multiple books, both glued and sewn, delivered to my house, unpacked and left sitting overnight, only to find that by the next day the covers have warped significantly. The boards that were fine when unpacked ~12 hours prior seem to have curled up and no longer lie flat against the leaves, though I cannot tell if the cause is due to the boards themselves warping or the leaves warping and thus offsetting the boards.

I thought it might be a humidity-related issue, so I bought a hygrometer to check. The indoor environment is 70°F (21°C) at 26% humidity.

Apologies if this is not the correct forum for this discussion.

2lilithcat
Mar 13, 2021, 8:29 pm

This is absolutely the right place!

That humidity level seems low. All the sources I've seen suggest a higher humidity. Library of Congress says room temperature and 35% humidity, while the University of Chicago Libraries say 70ºF and 50% humidity. The Art Institute of Chicago suggests 68-72° F, with 40-50% relative humidity.

https://www.loc.gov/preservation/care/books.html
https://www.lib.uchicago.edu/about/directory/departments/pres/resources/caring-y...
https://www.artic.edu/library/discover-our-collections/research-guides/appraisal...

3-Ophidian-
Mar 15, 2021, 7:22 pm

So would low humidity warp and bend the covers like that?

4lilithcat
Mar 15, 2021, 8:52 pm

I think it's basically that there has to be a balance between the temperature and the humidity. I'm not an expert, though, by any means! And I am a bit surprised that the warping would happen so quickly.

5spiralsheep
Mar 16, 2021, 7:05 am

>3 -Ophidian-: Sometimes the speed of environmental change effects the outcome on materials. The faster the change then the more extreme the outcome. Any differences between retail / delivery / library conditions can be quite fast.

6melannen
Mar 16, 2021, 10:26 am

>3 -Ophidian-: Were they sealed in plastic when they arrived, and then you opened them? Like the >5 spiralsheep: said, rapid and extreme changes in humidity either way can do it. If they were sealed somewhere tropical and then you opened them in 26% that's pretty rapid and extreme.

If you unseal them slowly - leave them in their wrapping with just a few holes poked, or if they're in cardboard boxes, wait a week or so to open the boxes - that might help.

Also especially with softcovers, if you put weight on them immediately after opening (a stack of other books will do) until they've had time to equalize, that might also help.

7Glacierman
Mai 11, 2021, 1:40 pm

>1 -Ophidian-: A sudden change in temperature from cold to room temperature can cause this. During the winter, I prefer to allow book packages to come up to room temperature before opening them OR I go ahead an unpack the book, but leave it under weight while it warms up. The cold book will cause any moisture in the air to condense on it, even though you might not see it. That is sufficient moisture to cause warping. Such warpage can often be eliminated by putting the affected book under pressure, either under weight or on a bookshelf with other books to provide a firm pressure. It should return to normal w/in a few days.