Polyvinyl chloride

Fine art photographers and the studios that do their mounting
continue to use closed cell polyvinyl chloride sheets as mounting
panels. The most commonly used brand in the US is Sintra; other
brands of PVC sheet are: Komacel, Celtec, Trovicel, and InteFoam.
Recently there appears to be a shift away from Sintra to the use of
aluminum sheets and aluminum clad panels such as Dibond for the
mounting of photographs, but PVC is still often used.

These PVC products successfully replace wood based panels in many
signage applications, in large part because of their light weight,
and their use as a mounting material for works of art has naturally
evolved with the increased scale of contemporary fine art
photographs. Apparently some of the first studios with whom
photographic artists worked to print and mount their photographs
already used PVC sheets to cold mount photographs for advertising
display.

Over ten years ago we wrote the manufacturer of Sintra to find out
if any independent testing had been done to predict the aging
characteristics of the product. The threat of the formation of
hydrochloric acid was our primary concern. We received the results
of a test the company had commissioned in which (if I recall
correctly) pieces of Sintra were immersed in water and the pH of the
water compared before and after lengthy immersion. Though the
experiment demonstrated to their satisfaction that no HCl would be
formed in the presence of water, we were not convinced, and we have
continued to respond with caution when asked about its use.

Periodically I search Conservation OnLine to see if there has been a
study published addressing the question:  Is closed cell expanded
PVC safe to use as a mounting material for photographs and for other
works of art? I still haven't found more than passing reference to
the topic.

I would like to hear if any such work is being done or is
contemplated. Resolving the the PVC question one way or the other
would be a great service.

Jared Bark
Bark Frameworks
New York City


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                  Conservation DistList Instance 18:10
                 Distributed: Thursday, August 5, 2004
                       Message Id: cdl-18-10-024
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