Slide mounts for treatment documentation

Ellen Rosenthal <erose<-a t->servtech< . >com>

>My concern is about the potential long term effects of deteriorating
>paper mounts as opposed to deteriorating plastic, which would be a
>better choice?

I've used both cardboard mounts and the plastic mounts and would
lean towards the plastic ones.

The heat-sealable mounts from Kodak (at least in the late 1970's and
early 1980's) were made from what looked to be pretty unpurified
cardboard. The cardboard was very brown with a nice white paper
outside.

However, we have generally found that chromogenic color tends to be
a little less sensitive to poor quality paper than black-and-white
(silver) and the slide mount is not in direct contact with the
image. I also haven't seen any noticeable edge deterioration in old
slides from the 50's and 60's in cardboard mounts. Also, unless
they're stored under good conditions, the slides will be fading
anyway.

On the other side of the issue, I expect that harmful materials are
migrating from the contact areas (including the unknown heat-set
adhesive.) Also, the stability of chromogenic slides has improved
significantly since even the early 1980's and we may see
deterioration from the edges in the future in more recent materials.
(It is possible that such deterioration may have been swamped by the
natural, rapid fading of the slides in the early days.) If you are
trying to store the images to last, then I assume fairly decent
storage conditions and the slides will tend to be less sensitive to
harmful materials. (I often tell people that under good storage
conditions we can be forgiven more for small sins such as so-so
quality enclosures and that changing the enclosures can be done as
time and money permit rather than being a high priority.) Even if
the slide mounts prove to be okay for the slides, if it takes extra
effort to add poor quality materials to your collection, why do it.

As for the plastic mounts, I had a discussion about them with R.
Scott Williams at CCI back in the late 1980's. As he pointed out,
the only two plastics that would really work with automated slide
mounting machines would be PVC or polystyrene. None of the mounts
that either of us had looked at were PVC and all seemed to be
polystyrene. We both consider the polystyrene to be pretty benign
and the history with polystyrene (film) plastics and polystyrene
film reels seems to support that feeling. There also shouldn't be
plasticizers in the mounts nor are adhesives used (as in the
cardboard mounts.)

It's all opinion, but my experience has been that the plastic mounts
are less potentially harmful than the cardboard mounts (even though
I haven't yet seen damage that I can specifically identify as being
caused by the mounts.)

Douglas Nishimura
Image Permanence Institute

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                  Conservation DistList Instance 11:38
                 Distributed: Monday, October 20, 1997
                       Message Id: cdl-11-38-001
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