Polaroid prints

Mr. Reynolds;

All Polaroid print and negative materials have a small pod of chemistry
that is spread over the print as it is either pulled through a set of
rollers in a film holder, or is ejected by the camera itself after
exposure.  The basic difference in these films is that either the print
is pulled apart from a paper negative material by the photographer after
development is complete, or all of the chemistry remains inside a sealed
packet under the image.  The print simply develops before your eyes, the
process stopping by itself at the appropriate time.

I believe all of the peel-apart materials for amateur use have been
discontinued (there were a number), while all of the current "pro" films
(except for soon-to-be-discontinued pro chrome, an E-6 compatible film)
continue to use the peel-apart technology.  The current generation of
Polaroid amateur films all are of the sealed packet type.  This type of
film was introduced in 1972 as SX-70 film.  It was discontinued in 1976,
but replaced with similar films (Time Zero, Spectra, Spectra HD, etc.).
Kodak actually produced an instant sealed packet print film for a time
in the 1970's.  It was discontinued when Polaroid sued for patent
infringement (Polaroid won the suit).  These can be identified by the
rigid textured plastic on the front of the image.  Polaroid materials
use a glossy polyester cover for their packet type films.

*All* Polaroid color materials are less stable in terms of light-fading
than chromogenic color prints.  In dark fading, they will develop a
yellowish stain.  The packet type amateur prints develop more of this
yellowing than the peel-apart variety as well as having a tendency to
develop cracking over time (especially in dry conditions).

These materials should have no detrimental effects on surrounding
materials that I can anticipate.  The sealed nature of the amateur films
should tend to keep in most off-gassing should any occur.

>From an archival perspective, I would not let worries about the
stability of materials keep you from documenting something by adding it
to your collection.  I would not, however, purposefully document
anything meant for the archival record using Polaroid materials.

Hope this helps.

Yours,
Loren C. Pigniolo
Photographic Preservation Specialist
Photographic Preservation Services
415/665-1827
800/484-9808 x7841

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                  Conservation DistList Instance 7:29
                 Distributed: Saturday, October 2, 1993
                        Message Id: cdl-7-29-002
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