Abstract: A paperboard container principally for the storage of large, relatively heavy items such as x-ray files, and the like, comprises a box structure having a bottom and upstanding end and side walls formed of multiple layer construction enabling the structure to be extraordinarily strong and rigid and particularly adapted for stacking. The box structure is formed from a pre-cut, pre-scored blank which includes an integrated cover and is self-locking to avoid the need for stapling or gluing. A separately formed partition cooperates with the box structure to divide the interior thereof into separate compartments as well as to enhance the rigidity and stacking strength of the container. The bottom of the container is formed by a continuous, uninterrupted panel so that it can be slid, even when loaded, without endangering its structural integrity.