Earlier today I had a brief Twitter conversation with John Resig about storing art, specifically prints. I thought I'd share a few additional thoughts that didn't quite fit into the space of 140 characters.
Disclaimer: I'm no conservation expert and my art isn't particularly valuable. If in doubt, consult a pro.
The best method, I think, is to have your prints archivally framed and hanging on the wall. You can enjoy them and they're relatively safe from damage. Unfortunately, framing is expensive and we only have so much wall space.
Although it's common practice to ship prints in tubes, you should store them flat if at all possible. It's almost always possible to flatten out a print, but in my experience the paper tends to develop a memory. The longer it's rolled, the harder it is to flatten out without developing waves or ripples.
Flat Files
The obvious storage solution is a flat file cabinet. Flat files make it very easy to simply lay the prints in the cabinet and be done with it. However, flat files are big, bulky furniture. The biggest commonly available size is 36" x 48", which is a lot of real estate in your room. And remember, that's the outside dimension — the largest print you can accommodate will be more than an inch smaller.
Flat files are also fairly expensive, though careful shopping on Craigslist or the like may turn up something useful.
All that said, if you can swing a flat file, it's the way to go for safe, bulk print storage. I love mine.
Within the cabinet, some folks like to store prints in mylar sleeves. I tried this route and found the hassle and cost outweighed the utility: the sleeves don't always lie entirely flat and I couldn't stack prints without inducing some waviness in prints on lighter-weight paper.
I ended up taking the prints out of the sleeves and instead simply place prints on top of each other, alternating with sheets of acid-free blank paper.
Portfolios
For prints up to 24" x 36", art portfolios with slip-in sleeves work great for storage. The stiff covers provide good protection for your prints, but make it easy to page through and admire your collection. They also can slip under a bed or, if you're careful, lean against the back of a closet. Watch out for pests and spills, though.
I like the Itoya 18" x 24" Profolio and Profolio Evolution. This is a common size for gigposters, so the vast majority of my collection fits in these easily.
There are bigger portfolio cases. I have a 24" x 36" Stein deSign Picturesque Presentation Case. Pricey, and only comes with 5 sleeves, though you can expand up to 20 sleeves with "refills". On the other hand, it's a very sturdy alternative to a flat file for storing larger prints.
You may also be able to find fold-over artist portfolios in even bigger sizes. They don't typically have sleeves to help organize your prints or hold them in place, so you need to be careful about handling. Look for acid-free materials.
DIY
I have a few really long prints that don't fit in any of the commercially available, affordable solutions. So I made my own folders — basically a variation on the fold-over portfolio.
Get some 40" x 60" acid-free foam core boards and some acid-free hinging tape used for framing.
Put two boards on top of each other and tape one edge together, creating a hinge.
Carefully place the prints between the two boards. For added peace of mind, you might want to temporarily mount the prints on heavy acid-free backing paper using framer photo corners or clear mounting strips.
Hold the entire thing closed with big-ass rubber bands or similar. Handle the whole thing carefully — contents are likely to shift.
Get Your Own Art
Hand-made prints — screen prints, woodblock prints, and lithographs, usually — are a great introduction to the world of art collecting. There's something everyone. I really like Andy Warhol's Cow Wallpaper, but that's not going on my wall any time soon.
Instead, I accidentally fell into the rock art gig poster scene. You can learn more about it at gigposters.com and Expresso Beans, two of the more active communities for artists and collectors.
John, by the way, has his own fascinating site cataloging Japanese "Ukiyo-e" woodblock prints.