Composite blends of PBAT (or another similar polyester) with PLA and a carbohydrate-based polymeric material. While PLA is not compostable under home composting conditions (e.g., temperature of 28° C.) on its own, when blended in the manner described herein, it is compositable under such conditions. The addition of the PLA increases the rigidity of the composite blend, as PBAT on its own is so flexible as to be problematic for use in carryout bags, and the like. An exemplary blend may include 30-55% by weight of the carbohydrate-based polymeric material, up to 20%, or up to 15% by weight of PLA, with the balance of polymeric content being PBAT (e.g., 30-60% PBAT). Other components (e.g., an inorganic filler, such as calcium carbonate) may also be included in the blend.