Tracing paper

I am currently interning at the Canadian Center for Architecture.
I've been asked to investigate mysterious oily-looking stains on
interleaving paper and folders that house architectural drawings on
tracing paper. I don't have exact dates for the drawings, but the
stains have appeared on folders in two separate archives of Canadian
architects recently acquired by the CCA. None of the drawings
examined display yellowing, suggesting they may be fairly recent.
The first archive covers a period from 1947 to 2002.  At this time
the exact dates of the drawings on tracing paper that are causing
the stains are unknown. The second archive, also acquired recently,
has stains on a folder marked with the years 1987-1999.  I hope to
contact the architects to see if we can identify the manufacture(s)
of the papers and advise them *NOT* to use this type of tracing
paper.

Upon their arrival at the CCA, these two archives were rehoused in
standard storage material and the stains were noticed not too long
after. The stains are especially pronounced in positions
corresponding to the perimeters of drawings.  It looks as if when
several folders are piled one on top of the other the weight causes
oil the be squeezed into the adjacent interleaving paper and folder
stock.   Tests of stained areas of folder stock and interleaving
paper with FTIR show the presence of mineral oil.

Oiled tracing paper are not uncommon but I was wondering if anyone
has dealt with stains resulting from mineral oil before, and in such
recently produced papers?  Some of our questions are:  how should we
store these drawings to prevent them from damaging other collections
materials and each other;  Can we identify the presence of mineral
oil in recent tracing paper drawings BEFORE damage to adjacent
materials shows, so that we can separate them from other collections
materials before they cause damage?

Jessica Regimbald
Intern, Conservation/Preservation
Canadian Center for Architecture
Montreal, Canada


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                  Conservation DistList Instance 26:9
                  Distributed: Saturday, July 21, 2012
                        Message Id: cdl-26-9-017
                                  ***