I would like to graciously thank those collectors who avoid everything larger than 8.5x11 and leave such wonderful items to the rest of us.
Odd how automobile or bottle or brick or beer can collectors do not seem to have these same blinders on. Some of the most incredible collectibles in every hobby are large or 3-dimensional. Happily as mml notes the art world has solved many of the storage challenges for large flat/paper items.
One of the best purchases I ever made for storing things was a used blueprint cabinet found at an auction of a retired architect. The drawers are slightly larger than 30"x40" which works for maps, posters, newspapers, sheet music, rocks, and even a large glass serving tray! Cool, dark, dry, and dustproof.

And it works great for riker trays of small items!
