Abstract: A collapsible bag which is adapted to have another bag stacked thereon when the collapsible bag is filled with material. The collapsible bag includes a main body, a bottom portion, and a top portion. The main body defines a plurality of vertical sections to provide columnar support for holding the bag upright when the vertical sections are substantially filled with material. The bottom portion depends from the main body and includes at least one bottom seal for closing the bottom portion, wherein the bottom portion defines a substantially planar base. The top portion extends from the main body at an end opposite the bottom portion. The top portion includes a top seal for closing the top portion. The top portion defines an interior space within the bag between the top seal and an imaginary fill line.