Abstract: A stackable storage bin having a collapsible six-fold sidewall structure which, when opened, defines a vertically-oriented rectangular tube which removably cooperates with upper and lower pallets for defining a closed storage compartment. The sidewall arrangement has the end and side walls constructed of at least a three-ply laminate defined by inner and outer layers fixedly and coextensively secured to opposite sides of an intermediate layer. The inner and outer layers each include inner and outer facing sheets joined by transversely extending ribs therebetween. These inner and outer layers are entirely of plastic and are preferably formed either as a profile extrusion or as a double-faced corrugated sheet. The intermediate layer is of a light-weight rigid foam.