I use two different methods for storing posters. I use large, clear, two-handled, portfolio-style poster holders (about $13 each). I purchased mine from a catalog, but they can be also found in most stores that carry educational supplies. They hold large numbers of posters and can be hung up anywhere. Last Christmas, I purchased a tall plastic container (about $10) to hold wrapping paper before discovering that it didn't fit in any of the closets in my house. I took it to school and found out it was ideal for larger posters. I just roll the posters up, slide an elastic band around them, and pop them in. I can fit in quite a few posters. The container tucks away nicely in a spare corner.