Sleeve with a triangular lower end

A tubular sleeve initially constructed in a flattened condition and openable therefrom, comprising:

• a body having an upper end, a triangular lower end, a first sidewall edge, a second sidewall edge, and an inner space and the body further comprising a lower portion and an upper portion, wherein the upper portion is detachable from the lower portion, the body, when the sleeve in the flattened condition, having a terminal vertex in the triangular lower end where the first sidewall edge and the second sidewall edge converge, the terminal vertex having a terminal vertex angle which faces inwardly and has an angular dimension greater than about 30° and less than about 160°, and the first sidewall edge having a first vertex which has a first vertex angle which faces inwardly and has an angular dimension greater than about 100° and less than about 165° and the second sidewall edge having a second vertex which has a second vertex angle which faces inwardly and has an angular dimension greater than about 100° and less than about 165°, and wherein a lower segment of the first sidewall edge, a lower segment of the second sidewall edge, the first vertex, the second vertex, and the terminal vertex cooperate to define the triangular lower end, the triangular lower end having an infolded gusset therein, and the body of the sleeve having a generally frustoconical shape when in an opened condition.