Abstract: An upright, or "pop-up", box dispenser having a curvilinear opening for dispensing thin sheets of paper such as tissues or non-woven products. The curvilinear opening may be in the shape of an "S", multiple "S" shapes or arcs. Preferably, the effective open area of the curvilinear opening is about 2.5 square inches or less. Typically, the curvilinear opening is incorporated into a thin plastic film overlaid on the top of a cardboard box.