Tyvek

We have been using Tyvek envelopes for temporary enclosures for
books, primarily those in poor condition that are going to our
off-site facility. We happened to test one with our "Abbey pH Pen"
(Chlorophenol red) and have a positive (light yellow) result for
acid.  Should this be of concern?  Does this acidity transfer to the
contents? Do we need to be more careful about our supplier of
envelopes?  Are their different grades/types to specify? Any
suppliers to recommend?

The Cons DistList archives have a lot about Tyvek but I don't see
anything that addresses this particular issue.

Carl T. Stewart
Acting Department Head
Library Technician--Brittle Books
Preservation Department
University Libraries
184 UCB
Boulder, Colorado 80309-0184
303-492-2249 wk


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                  Conservation DistList Instance 15:63
                  Distributed: Tuesday, March 19, 2002
                       Message Id: cdl-15-63-026
                                  ***