Brownprints

We have a large collection of rolled architectural drawings from a
shipyard, dating from the 1880's to 1960. They are housed in their
original cardboard tubes. The tubes are capped with mostly snug
fitting cardboard caps. We are doing an inventory of the tubes,
based on the information written on the outside of the tube. We have
time to "spot check" the contents of about every 20th tube to verify
that the information written on the outside is correct. This
checking is done by opening the tube, unrolling the drawings and
checking them individually. Eventually, when we acquire more space,
we plan to rehouse the collection.

While most of the drawings are "linens" or ink on drafting cloth,
some are blueprints, diazos and Van Dykes. The Archivist performing
the inventory has noticed a strong "stale chemical" smell when
opening the tubes containing mainly Van Dyke drawings. The smell is
distinct from the diazo chemical smell, and it is not a vinegar
smell either. The Archivist reported that when he opened the tube
and examined the drawings, as he bent closely to view the title
block, he noticed a stinging sensation near his face, his eyes felt
a slight burning, and he felt slightly nauseated. These symptoms
went away as the after the drawings were out of the tube a few
minutes. Previously, the drawings had not been removed from  their
tube for many years.

I have noted that Alan K. Lathrop, in his article, "The Provenance
and Preservation of Architectural Records," [from the American
Archivist, summer 1980], states that, "Another process used for
reproduction of drawings was the Van Dyke or brownprint (also called
sepia), invented by F.R. Van Dyke in 1901. The paper stock was
sensitized with silver and developed in sodium thiosulphate."

Finally, here's my question: has anyone had a similar experience
with formerly well sealed up Van Dyke drawings? Are there any known
risks involved with being exposed to this type of drawing? How
should they be handled? Can access be provided to these drawings if
reformatting is not an option at this time?

Erica Schoenhals Toland
Archivist
Historic Documents Dept.
S.F. Maritime NHP
Fort Mason, Bldg. E, 3rd floor
S.F. CA  94123-1314
415-556-9876
Fax: 415-556-3540

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                  Conservation DistList Instance 11:83
                  Distributed: Tuesday, April 14, 1998
                       Message Id: cdl-11-83-011
                                  ***