Abstract: A bulk container is formed from a blank of corrugated sheet material having wall fold lines demarcating end wall panels and side wall panels, and flap fold lines demarcating top and bottom closure flaps. A T-shaped slot in the blank separates adjacent closure flaps from one another. A first portion of each slot extends inwardly from the free outer edges of the closure flaps and terminates at a second portion which extends substantially perpendicular to the first portion. The first portion of each slot is substantially aligned with a corresponding wall fold line. The second portion of each slot extends substantially colinearly with a flap fold line. The slots reduce binding and bunching of the thick multilayer reinforced walls found in conventional bulk container constructions, and at the same time avoid formation of through-holes at the corners of the container.