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>Does any know how to prevent further decay in books with acidic paper?
>(Please don't tell me to store them at absolute zero or in an oxygen free
>atmosphere for ever...)

Ok, I won't.  but seriously, as a practical matter, environmental
control is probably going to be your biggest bang for the buck.  As a
rough rule of thumb, if you lower the temperature by ten degrees F
(yes, that really is F.  If you want an explanation of why, I
will have to do some homework), and if you can keep that lowered
temperature pretty constant, avoiding diurnal or seasonal swings, you
will effectively double the life of the paper.

What follows is off the top of my head, after a very long day, so bear
with me if I blow a fact or two.  If you (or anyone) want more info on
any of this, just let me know and I'll fill things out a bit better.

As other posters have mentioned, there are several processes under
development for neutralizing or strengthening paper (these are
separate processes, but the effects are strongly interconnected).  All
of these processes are still in the R&D stage (note that this is my
opinion, not that of the manufacturers, some of whom are actively
marketing their products).  As libraries are the principle users of
these services, we have taken an active interest in their development
and are being very conservative (not enough so, for my money) about
exposing our collections to any of them.  The history of library
conservation has been, to a large extent, the history of wonderful
innovations that have later proven to cause problems of their own, and
a large part of my work as a conservator is undoing the effects of
previous generation's innovations.


The Library of Congress has developed a process involving diethyl zinc
depostited in a large vacuum chamber.  The results have been very
promising.  They have recently issued a Request for Proposals to
vendors of competing processes to submit those processes to a
rigourous testing and evaluation program.  I don't know how long this
will take, but it will be a while yet.  In any case, the diethyl zinc
process, which has been licensed to Texas Alkyls, will probably not
make it down to the individual consumer level in the forseeable future.
(In fact, at this point, I'm not certain that anyone has offered it
to libraries in general).

There are several other promising processes, one of the most venerable
being Wei To, which is really a family of processes all of which have
consist of a Magnesium Alkoxide in a solvent.  Delivery systems range
from sprays (individual aerosol cans for casual work and production
systems with spray booths and compressors for larger scale projects)
up to largish chambers (similar in design to dry-cleaning systems).
Wei To was created by Richard Smith (who was the one who explained to
me about the 10 deg F business above, and will probably be irritated
that I've forgotten it) and has since been sold to one of the big
chemical companies (DuPont?).

There are also several newer processes that are similar to Wei To, but
differ in specifics.  Since I can't remember all the companies
involved, and since none of them are offering services to individuals,
I'll be polite and not mention any of them.  Preliminary indications
on this group of processes is promising.

There are a couple of other processes floating around that I'm not so
enthusiastic about, most of which involve amines in one form or
another (over the past 40 years or so, several attempts have been made
using amines, but they have all had one or more major flaws, the least
of which being impermanence of the treatment (ie you have to repeat
the treatment periodically, which makes it too expensive for

For the indidual, it *is* possible to have indivual books (or
manuscripts, typescripts, artworks, etc) treated, but it needs to be
done by a professional conservator (which is not by any means cheap)
because there is a real possibility (even probability) of damage.  If
you want to follow up on this avenue, I will be happy to help you find
someone qualified.

Strengthening:  The monomolecular coating someone else mentioned is
called paralene and was developed by Novatran for use in the
electronics industry (the first paper I saw on it was called "Paralene
Conformal Coating for Hybrid Microelectronics").  The process deposits
a thin layer of poly-paraxylene (if I recall correctly, for paper it
is usually in the range of 1-5 microns thick).  The result is quite
impressive, and the paper (at least with thinner coatings) retains a
nice paper-ish feel.  There is a firm called ICI (Information
Conservation Inc) in North Carolina that offers the service to
libraries, but I don't know if they deal with individuals.  Paralene
is especially promising for paper that is already so severley
deteriorated that nothing can be done for it (eg fire damage).
Definitely still in the development stage, as we really don't know
enough about its long term aging but very promising (and for the
hopeless cases, certainly better than nothing, even if there do turn
out to be long term problems).

There are other strengthing processes in the works, mainly in the UK,
involving graft polymerization.  I haven't actually seen anything
treated this way.  I think it is taken pretty much as a given by those
of us who have been looking at the problem of embrittled paper, that
eventually we will see a method of alkalizing and strengthening paper
at the same time (next couple of decades maybe).  At least one of the
currently proposed mass deacification processes appears to offer a
degree of strengthening as a by-product, but not of the order that
would be required to make a brittle paper usable.

I will be happy to elaborate (via email) on any of this and will send
citations, articles, etc, if youre really interested, but I think I'd
better stop now before this becomes too utterly boring to live.

Walter Henry
Assistant Conservator
Stanford University Libraries

Naturally I neglected to mention a whole category of alkalization
techniques, the ones I actually use most.  Paper is marvelously
washable, and among the benefits is a reduction in free acidity.  Done
properly (and again, it is possible to do great damage) it can be one
of the most effective means of enhancing both the longevity and the
practical characteristics (flexibility, etc) of paper.  In most cases
we follow washing with alkalization using calcium hydroxide or
magnesium bicarbonate, depending on the nature of the artifact (there
are other agents used but these two are the most common these days).

Walter Henry
Assistant Conservator
Stanford University Libraries

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