Abstract: A stackable container formed from a sheet of material that is die-cut, for example, and folded to form an open box having a bottom, side walls, and end walls having extensions. Crests formed on the upper edges of the end walls and the extensions provide double-thickness crests when the extensions are folded back onto the inside of the end walls. The double-thickness crests fit into corresponding holes made in the lower edges of the end walls of the open box, such that another similar box can be set securely on the upper edges of the box. Thus, a plurality of boxes can be superimposed, fitting one on top of another, to form stable stacks. The extensions are divided vertically into a first section, a central section and a final section. The extensions are folded inside the box to form prism-shaped reinforcements, the central sections being folded at an oblique angle across the corners of the box.

Abstract: An economic stackable container of foldable corrugated material with improved strength for forming a stable stack of containers. Ventilation spaces are provided between stacked containers. The arrangement of panel is disclosed. An extension formed at the top at each corner projects into a notch formed at the bottom of a respective corner of the container above. The panels are particularly reinforced by folded panels at the corners. A separate reinforcing sheet is applied around the periphery of the panels of the main sheet. The sheets have their corrugations in the various panels oriented for strength.