Overhead projector transparencies

Melanie Nief <melanie-nief [at] gmx__de> writes

>I received an artwork from 1996 for conservation, which consists of
>overhead projection transparencies, printed black and white. Does
>anybody have any experience with this material? I wonder what type
>of plastics the transparencies are made of and whether the material
>has changed during the course of time. The foils used for this
>artwork are totally transparent and do not seem to be coated on
>either side. The most important questions are how to clean them from
>surface dirt and fingerprints and what storing conditions are
>suitable. I would be very grateful about any information or shared
>experience about this subject.

Overhead transparencies from 1996 are most probably going to be
either electrophotographic (photocopier or laser printer) or inkjet.
Dye sublimation printing has also been used for this application, if
not as often. If the transparencies are not coated, they are
probably electrophotographic. In this case, the film is probably a
cellulose acetate.

I would recommend you identify the printing technique by examining
the objects under a microscope; if you need help with this, the
students at the Akademie der bildenden Kunste in Vienna know all
about these processes since they had a workshop on the subject last
summer. You might consider contacting Ms. Sigrid Eyb-Green at the
Akademie for this.

Once you know which process it is, you can come up with an
appropriate cleaning proposal. Since the three processes have
different sensitivities, the best cleaning options may be quite
different. The electrophotographic transparency will be heat and
solvent sensitive, but not very water sensitive. The inkjet
transparency will probably be very water sensitive. The dye
sublimation print is, unfortunately, sensitive to almost anything!

Martin Juergens
Photograph Conservator
Margaretenstr. 29a
20357 Hamburg, Germany


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                  Conservation DistList Instance 21:39
                 Distributed: Sunday, January 20, 2008
                       Message Id: cdl-21-39-003
                                  ***