Binder's board

Ursula Kolmstetter <ukolmstetter [at] ima-art__org> writes:

>... assumed that they are acid-free. But they are not.  Our conservator
>for works on paper did a test and found that they are not acid-free.

We should distinguish the term acid-free from pH neutral.  At a pH
of 7 or greater paper still contains a small fraction of acidic
groups.  This fraction is dependent on the pKa of the buffer.
Consequently material that is buffered but contains acidic groups in
any form cannot be "acid-free" but should instead be labeled pGH
neutral.

If the term-acid free is used, it probably should be reserved for
organic materials (such as cooking oil or paraffin) which contain no
acidic groups in any form.

Dr. Mark Mizen
Director of Technology
The Antioch Company

                                  ***
                  Conservation DistList Instance 13:11
                   Distributed: Friday, July 30, 1999
                       Message Id: cdl-13-11-009
                                  ***