Bleaching

Tracey Heft <trace [at] eclipsepaper__com> writes

>I have some papers that need to be bleached but *cannot* be bleached
>in an aqueous environment. ...

If you say that there are objects that "need" to be bleached you
have created a  directive that is likely to set you up for negative
experiences. It gives you more discussion options to say that there
are objects where bleaching of their paper support may be
aesthetically desirable but where for technical reasons bleaching
may or may not be feasible.

If bleaching is technically inadvisable because it would cause
severe side effects, i.e. be detrimental to the long-term material
stability of the object (and, ultimately, its appearance), the
conservator will have to be able to explain the reasons for this
bleaching abstinence to the client.

As to non-aqueous bleaching: Bleaching, to minimize its considerable
risks, always requires the use of liquid water/aqueous solutions,
i.e. no bleaching without washing. To summarize the principle steps
of the process which follow upon a thorough cultural and technical
evaluation of the object to clarify the goals and methods of
treatment implementation: removal of water-soluble degradation
products by washing, implementation of an alkaline reserve aimed at
protecting the paper during bleaching, the bleaching process itself,
removal of the bleaching agent through extensive rinsing in
appropriate aqueous solutions, and finally, application of an
alkaline reserve. If these steps cannot be appropriately
implemented, it is inadvisable to embark on this complex and highly
invasive paper conservation treatment. See also Restaurator Journal
2009/04.

Prof. Dr. Irene Bruckle
Staatliche Akademie der Bildenden Kunste Stuttgart
Stuttgart, Germany


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                  Conservation DistList Instance 24:3
                  Distributed: Wednesday, June 2, 2010
                        Message Id: cdl-24-3-001
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