It's pretty simple though. almost everything likes cool/cold and dry. Not real dry--it depends on what the material is, you don't want to dry it out so much that it falls apart, but high temps, high humidity are the arch-enemies of storage. what you need is a worst-case scenario test, that would show you how bad it could get-- but this probably wouldn't make good ad copy....
again, it's kinda like the PAT. they stress the materials out. It's my understanding--vague--that plastic based materials can be destroyed in the process of the test. If the product has slip agents in it for example--like a plastic notebook sleeve. The plastic may be "safe" in that it won't cause any staining to the items inside. But the nature of the beast is, that under the right conditions--higher temps, humidity and pressure--the slip agents can leech out onto the surface of whatever is stored inside. It doesn't "harm" the item anymore than that you can't remove it, but, that's a finer point.......
One manufacturer had a disclaimer for awhile listing the ranges of conditions applicable for use of a product. It was basically the ANSI standards I posted above. Cool & dry. Cold. The disclaimer was a footnote on a website--the packaging doesn't mention these guidelines.
How much do you suppose they'd sell if they said you had to use it in conditions under 70 degrees F and 50% rh constant, and avoid excess pressure on the surface if items are stored within?
OTOH--very easy to call something "archival"....my pictures will last forever!
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