I have matted 8x10 and 5x7 prints that I need to display and I'd imagine your items would be of a similar shape.
What I've found and love are these:
http://www.ikea.com/us/en/catalog/products/70154800/Theoretically it's a pot lid organizer, but I've found that I can stand my prints in the spaces and my customers can flip through them easily. The upright pins screw on and off, so they are very compact when storing them after the show. Because they expand and contract, I can adjust the overall length of the display so that it doesn't ever look like I have a half-empty display. ;)