A container blank, a stackable container, and a method for making a stackable container are disclosed. The container blank includes a base having first and second pairs of opposed base edges, end walls foldably attached to the first base edges, and side walls foldably attached to the second base edges. Each side wall has an outer wall foldably attached to the second base edge along a first fold line, at least one index fold-down flap attached to the outer wall along a second fold line, and an inner wall or inner wall flaps foldably attached to the outer wall along a third fold line. Each index flap has a distal portion with notched or expanding extensions, and optionally, a border at a first angle of less than 90 from the second fold line. The stackable container is made from the container blank (e.g., by the method).

The present invention relates to a blank and a box obtained from such a cardboard or corrugated-cardboard blank, comprising a succession of four leaves that are connected together in pairs by first folding lines, specifically two end leaves that are separated by two intermediate leaves, and comprising on each side a set of rectangular flaps. One intermediate leaf comprises at least one opening adjacent to a first folding line joining to an end leaf, the adjacent end leaf comprising, on its peripheral edge opposite the first folding line, at least one tab which has a shape complementary to the opening, is located in line with the opening and is connected to the leaf by a second folding line parallel to the first folding lines.

Methods and apparatus for removably or irremovably interconnectable building block containers such as those capable of initially storing consumable items such as food and drink. After consumption of the food or drink, the cavity containing same may be cleaned and/or refilled with consumable or non-consumable items. The building block containers are utilized as building block toys and may be manufactured or otherwise designed to be collectable. In one aspect, the container connectors are nearly identical such that any one connector may mate with any other connector. In another aspect, the connectors are nearly identical but the orientations of each connector vary to allow mating to occur when the connectors are properly oriented. In another aspect, the container is a cube juice box with connectors on all four corners of all six sides of the container. A frame for holding a juice container may also be utilized.