StoreMoreStore has many fantastic poster storage options including cubby shelves, flat file cabinets and hanging folders.
Flat File / Flat Files Cabinet for Paper Print Poster Art
Spacesaver Flat File Cabinets
Blueprint Storage, Blueprint Racks, Blueprint Cabinets, Blueprint Organizers, Drawing Storage, Blueprint Boxes, Blueprint Bags, Flat Files - EngineerSupply
Blueprint Flat Shelf Storage Racks Over-sized Architect Plan Drawing Shelving Shelves
Protect and store your art work, drawings or biological collections. These flat files hold papers up to 24 x 36. The inside of the drawers measure 37W x 24-3/4D x 1-1/2H and feature full extension glides. Up to three units can be stacked providing you with ample storage. All three pieces are interlocking to each other or can be independent of each other. Start with the 4 toe kick which is covered with rubber base molding.
Diversified Woodcrafts FFS-3624M Flat File, Stackable Maple
Heavy-Weight 20 Pt. File Folders - Hollinger Metal Edge
Quill Brand® Commercial 5 File Drawers Lateral File Cabinet, Locking, Gray, Letter/Legal, 36W (2174
poster storage – The Store Blog
Museum Racks and Cabinets Archival Bulk Storage, Shelving, Flat File