Abstract: A collapsible, self-erecting hollow structure which is formed from an integral blank of paperboard which is cut and scored to form a plurality of side and end walls which when erected form the hollow structure. Each of the plurality of side and end walls are hingedly connected along one edge thereof with at least one other wall. The hollow structure also has at least two flaps, each of which is hingedly connected along one edge thereof with at least one of the plurality of side walls. These flaps each is cut and scored to form an attachment and further is folded and affixed to one of the plurality of end walls on the side thereof which is interior of the erected hollow structure. An elastic means such as a rubber band is secured under tension to the attachments and normally pulls the two end walls to which the flaps are hingedly connected toward one another and thereby erecting said hollow structure. The hollow structure may also have affixed to it a copy extender.