Re: preservation of negatives/slides/prints
Mold and humidity are already mentioned in my post from
yesterday. If the mold grows, the humidity is already too high
for archival storage of any image material.
I have received quite a few emails requesting a new product
like Tetenal Mirasol 2000, which is a wetting agent with
biocide agents mixed in. I've considered several options, but
am not doing this, primarily this concept is misleading or
even deceptive. This is because if the humidity is high enough
to grow mold many other modes of degradation (such as that in
support, sizing material, gelatin binder or silver image
itself) can happen just as fast. Therefore, adding any biocide
to the wetting agent will only generate false perception that
it is good for storing images.
There are some cases where I see people have mold problems
with films processed by minilabs and not in the hand processed
film. The details depend on the machine design and the
chemical kit used by the establishment, but in many machines,
the final rinse bath is regenerated and reused. There is a
degree of variability in the technical sophistication that
went into the system, in the final rinse stage alone. Most
advanced systems would filter the water, use ion exchange
resin to remove impurities, and add dye stabilizer and other
agents, including bactericide. The final rinse water is very
easty to get rotten otherwise. So, the cleanliness of the
final rinse water (and the film you get) depends on proper
machine maintenance and right chemical kit.
I usually recommend people in high humidity area to get
several large size "Lock & Lock" or "Snapware MODS"
AIRTIGHT/WATERTIGHT containers made from polypropylene. These
food storage containers are pretty durable and they have
gasket to ensure tight seal. Put your collections in them
along with silica gel and perhaps molecular sieves. They are
not quite Light Impressions products and cheap. They are not
endorsed by anyone to be suitable for archival storage, but
they are made from food grade polypropylene.
Also, one of the Snapware MODS is perfectly sized for Polaroid
Type 55 shooters to carry sodium sulfite solution. If they
made big flat ones, I would keep print processing chemicals in
them as well. (It would also be nice to be able to shut the
lid while lith printing or using stinky toners.)
From: Peter Marshall <email@example.com>
Subject: Re: preservation of negatives/slides/prints
Date: Thu, 22 Mar 2007 22:05:01 +0000
> Another factor you don't mention that I'm having to recognize with all
> gelatin materials here is mould growth. It's especially bad on some
> trade processed slides, but I also get it on prints and negatives.
> Humidity is probably the vital factor for this, and I live in a poor
> area in this respect.
> So, despite the problems with digital storage, I think it is vital to
> get material worth keeping into digital form as soon as possible.
> Already many of my own images I think important are only printable from
> the digital files and many of the vintage prints show signs of degradation.