Our white Corrugated CardboardAudio Cassette Storage Box holds 20 cassettes in their cases with the spine up. Comes with a 3" deep cover. These boxes are very sturdy and are stackable. They fold together without tape or glue. We have an Archival Barrier Board Audio Cassette Storage Box for your more valuable tapes. Barrier board blocks migrating acids from coming in contact with the stored items. To go inside this box we have a six-cell partition also made from acid-free board.