Bleaching

Anand S. Akolkar <aakolkar [at] vsnl__com> writes

>Some authors in India on books  on conservation and preservation of
>paper materials advocate the use of bleaching agents like
>hydrochloric acid or bleaching powder for bleaching of the paper
>documents. Is it advisable to do so, and why/why not?

I would leave the arguments about bleaching old papers to paper
conservators and chemists but would like to make a few comments.

The hazards of using chlorine based bleaches in paper production
date back to at least 1829 when John Murray, the publisher wrote on
the subject. Papermakers did use bleach extensively and harmfully
although by the late 19th century some were making a virtue of
avoiding bleach. (e.g. our family at Hayle Mill launched RWS in 1895
and "unbleached Arnold" was well known).

Traditionally (up to the 19th century) I do not believe Indian
handmade papermakers used harsh bleaches. One of the notable
features of old Indian papers is that, unless attached by pests,
mildew or aggressive chemicals in inks and paints, they are usually
in very good condition and typically a pale buff shade. New papers
made from traditional materials in a traditional way have the same
shade. This may well have contributed to the collapse of handmade
papermaking in India as the new machine made papers were not only
much cheaper but could be very white.

Although some modern Indian papermakers do strive for whiteness for
the cultural reasons Reni Teygeler suggests, the majority do not.
Most Indian papers tend to be coloured (though the fibre may have
been bleached before dyeing or pigmenting it) and many are more or
less natural in shade. Those sold in the Indian market are often
white, reflecting the use of cotton rags purchased white and often
highly bleached with optical brightening agents in them as well.
Some papermakers do of course use chlorine dioxide or other bleaches
too. In such cases there is a considerable risk that the bleach has
not been adequately washed out since residual chlorine or its
compounds are likely to be damaging.

With regard to seeking advice, I would suggest initially reference
to The Institute of Paper Conservation
<URL:http://palimpsest.stanford.edu/ipc/>. IPC has published a lot
on bleaching. Its journals are in various institutions in India and
depending on various criteria Shri Akolkar may qualify for sponsored
membership.

As a co-founder of the Kumarappa National Handmade Paper Institute,
I should like to emphasise that its role is to help Indian
papermakers produce better, more consistent products and to help
their businesses flourish. Its success is reflected in the
papermaking boom in India, particularly in its export markets, over
the last ten years. It does not claim to have any particular
expertise in paper conservation and I would recommending pursuing
the subject of good practice on cleaning and stabilising paper with
conservators instead.

Simon Barcham Green


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                  Conservation DistList Instance 16:39
                Distributed: Tuesday, December 10, 2002
                       Message Id: cdl-16-39-002
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