A question about the mattes. Are they archival? I live in a area that can have some pretty strong smoke effects and all of my stuff with archival matting and conservation glass has come through fine. The two that I didn't know about archival matting are ok but not the best they could be.
The matboard is archival - I use Crescent matboard for nearly everything, and it is described by the manufacturer like this: "the cream core is made of unprinted, reclaimed wood pulp fibers and, along with the backing paper, is buffered and acid free". The backing can be hit or miss, as I use mat scraps, Elmer's foam board, or chipboard (like you'd find on the back of a drawing pad). The adhesive tape that touch the photo paper and attaches it to the matboard are considered archival and acid-free.
I check my older print stock from time to time, and I have only seen a very small bit of yellowing around the areas of the fibre and masking tape that holds the mat together, even on items that are 20 years old. I store my matted prints in my basement, which I keep cool and dry year-round.
I have not accounted for all environmental factors, though. I had not though about what effect smoke might have on any artwork, and as such, I couldn't say if any of the materials I use - matboard, backing, adhesives, or the print paper itself - would absorb such elements. It's better-protected in a plastic art bag or in a frame than it would be without it, but I am not sure what specific differences this might make on the longevity of the prints under adverse or strongly adverse conditions.
According to my personal evidence and asking at the local art museum. As long as all framing and mounting are archival acid free including backing materials, you can get a pretty good run of the 8o-100 years after that it is only aided by robust climate control of a vault. Of course that is the best storage option but then you can't show stuff off. And until I can get works framed I usually just store them in a acid free box with the wrap still on. *mutters need more wall space* Bookshelves and art are not compatible space sharers *sigh*