Abstract: An end closure construction for a tube-type container formed from a single paperboard blank, the blank having an extruded barrier layer coating on one surface thereof. The carton has at least one end closure which is flat and defined by end closure panels. To prevent excessive overlapping of paperboard layers at the center of the flat, closed carton end, each one of a pair of facing end closure panels is centrally recessed along its free edge. An abutment tongue on one of the facing end closure panels is bordered by a pair of recesses. Each of the recesses is spanned by the extruded barrier layer coating. The abutment tongue bears against the oppositely positioned barrier layer to form gussets, in a controlled manner, from the barrier layer.