Refrigerating books

Erma Loveland <lovelande<-a t->nicanor< . >acu< . >edu> writes

>Special Collections has a vellum book which is darkening around the
>edges and I am concerned that we are having a mildew attack.  We are
>working with the campus building maintenance people on a plan to
>control the humidity which fluctuates widely, even in desert-like
>West Central Texas. Until we can put the plan into operation, would
>placing these materials in a small refrigerator help?

I work in an archive with lots of vellum bindings; I have never
noticed the darkening you mention, but mould does sound likely--I
know parts of Texas get really humid!

Do you have a microscope, to see whether you can detect spores or
hyphae? Does it smudge off on the finger? If it's really damp,
vellum sometimes develops a faint tacky feel, and (as always) it's
advisable to dry out the mould before brushing it off so it doesn't
smudge the cover.

Mould has strict environmental requirements: if you get the
temperature below about 55 F., and/or the humidity below about 60%,
you won't have mould. Under the circumstances, I would hesitate to
refrigerate the volume, especially if it is at all frequently
consulted--vellum (as you probably know) is very sensitive to
changes and a rapid move from cold to room temperature could warp
the boards. A change in environment, whether temperature or humidity
(have you got any silica gel you could put behind it on the shelf?)
should only be undertaken if the book is under restraint, either
between other equal-sized books on the shelf, or under a weight.
Hope this is of some use.

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                  Conservation DistList Instance 10:68
                Distributed: Wednesday, January 29, 1997
                       Message Id: cdl-10-68-002
                                  ***