A method for making an additive manufactured foamed article (265; 319), the method comprising: Placing a foamable article (214; 216; 218) and carbon dioxide (CO 2) (240; 246; 604) in a vessel (234; 602), wherein the foamable article (214; 216; 218) includes a solid foamable material (210; 502; 620a; 620b) assembled using an additive manufacturing process comprising extruding at least one first filament or pellet comprising the solid foamable material (210; 502; 620a; 620b) to form the foamable article (214; 216; 218), wherein the solid foamable material (210; 502; 620a; 620b) is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers, and wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic polyurethane elastomeric homopolymers or copolymers; after the placing, maintaining the vessel (234; 602) at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide (240; 246; 604) is a liquid and the liquid carbon dioxide (240; 246; 604) is soluble in the solid foamable material (210; 502; 620a; 620b), and wherein the maintaining includes holding the article (214; 216; 218) and the liquid carbon dioxide (240; 246; 604) in the vessel (234; 602) for a duration of time sufficient for at least a portion of the liquid carbon dioxide (240; 246; 604) to infuse into the solid foamable material (210; 502; 620a; 620b) of the foamable article (214; 216; 218); following the maintaining and holding, optionally exposing the infused article (255; 256) to a second pressure and second temperature at which the carbon dioxide (240; 246; 604) remains infused within at least a portion of the solid foamable material (210; 502; 620a; 620b); following the maintaining and holding and the optional exposing, subjecting the foamable article (255; 256) to a third pressure and third temperature at which the carbon dioxide (240; 246; 604) infused in the solid foamable material (210; 502; 620a; 620b) phase transitions to a gas, thereby expanding the solid foamable material (210; 502; 620a; 620b) into a foamed material and forming the foamed article (265; 319). Placing a foamable article (214; 216; 218) and carbon dioxide (CO 2) (240; 246; 604) in a vessel (234; 602), wherein the foamable article (214; 216; 218) includes a solid foamable material (210; 502; 620a; 620b) assembled using an additive manufacturing process comprising extruding at least one first filament or pellet comprising the solid foamable material (210; 502; 620a; 620b) to form the foamable article (214; 216; 218), wherein the solid foamable material (210; 502; 620a; 620b) is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers, and wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic polyurethane elastomeric homopolymers or copolymers; after the placing, maintaining the vessel (234; 602) at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide (240; 246; 604) is a liquid and the liquid carbon dioxide (240; 246; 604) is soluble in the solid foamable material (210; 502; 620a; 620b), and wherein the maintaining includes holding the article (214; 216; 218) and the liquid carbon dioxide (240; 246; 604) in the vessel (234; 602) for a duration of time sufficient for at least a portion of the liquid carbon dioxide (240; 246; 604) to infuse into the solid foamable material (210; 502; 620a; 620b) of the foamable article (214; 216; 218); following the maintaining and holding, optionally exposing the infused article (255; 256) to a second pressure and second temperature at which the carbon dioxide (240; 246; 604) remains infused within at least a portion of the solid foamable material (210; 502; 620a; 620b); following the maintaining and holding and the optional exposing, subjecting the foamable article (255; 256) to a third pressure and third temperature at which the carbon dioxide (240; 246; 604) infused in the solid foamable material (210; 502; 620a; 620b) phase transitions to a gas, thereby expanding the solid foamable material (210; 502; 620a; 620b) into a foamed material and forming the foamed article (265; 319).