Rigid retaining bag

A bag comprising a plurality of adjacent bag cells, wherein each bag cell of the plurality of bag cells comprises:

• at least one flexible sheet of material;
• a back substantially orthogonal to a bottom, the back defining a back surface area and the bottom defining a bottom surface area;
• a top opposing the bottom, the top defining a top surface area;
• a front opposite the back;
• opposing sides, wherein at least one side of the opposing sides includes an envelope configured to receive a support structure therein, at least one side of the opposing sides includes a portion transverse to a plane defined by the top surface area and at least one of the opposing sides is associated with an adjacent bag cell of the plurality of adjacent bag cells, wherein the support structure comprises a rigid partition, the rigid partition forming an engagement with the envelope whereby the rigid partition is positioned in a planar relationship with the at least one of the opposing sides enabling the plurality of bag cells to be free standing when unfilled without the need for external support;
• wherein the bottom, the top, the back, the front and the opposing sides define a bag cell chamber, the top including an opening to the bag cell chamber;
• wherein the bottom surface area is greater than either the back surface area or the top surface area;
• and wherein at least one of the opposing sides is configured to expand laterally against a side of an adjacent bag cell responsive to a force applied to the at least one opposing side from within the bag cell chamber.