As a first year teacher, I needed something for my meager cache of posters. After talking to other teachers and looking at what they had, reading countless reviews on this website and others, and comparing different products, I finally decided on this Carson Dellosa Deluxe Bulletin Board Storage system. The reason I choice this poster storage system was because of the less degradeable material and the handles. It's not waterproof, but it is also not cardboard. This storage system does not stand up by itself like the huge and unweilding cardboard boxes, but with the handles, you can make use of that vertical space behind or between shelves or filing cabinets. I have mine between two cabinets that have the perfect amount of space. This poster storage system is plastic on the front and a breathable nylon type material on the back and handles. It will hold large posters and will expand several inches. I plan on purchasing a second one once I fill my first chart storage system up. Please hit the helpful button if you find my review to be helpful. I rely on reviews to help me choose which products to buy. Your feedback will help me provide quality reviews.