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 <petermarshall@cix.co.uk> 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.
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