A method of making a closed-cell foamed article, comprising a) forming an open structure comprising interconnected, unfoamed, thermoplastic polymeric members spaced to define openings therebetween by arranging at least a portion of the thermoplastic polymeric members in a repeating pattern; b) heating the thermoplastic polymeric members to a first temperature to soften the thermoplastic polymeric members and infusing the softened thermoplastic polymeric members with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic polymeric members without causing collapse of the structure; c) reducing the pressure to a second pressure below the first pressure while the thermoplastic polymeric members remain softened to at least partially foam the thermoplastic polymeric members; and characterized in that the method further comprises the steps of: d) heating the at least partially foamed, thermoplastic polymeric members to a second temperature below a temperature at which the structure collapses to soften the thermoplastic polymeric members and infusing the softened thermoplastic polymeric members with a second at least one inert gas at a third pressure that is sufficient to cause the second at least one inert gas to permeate into the softened thermoplastic polymeric members; and e) reducing the pressure to a fourth pressure below the third pressure while the thermoplastic polymeric members are softened and at a temperature below a temperature at which the structure collapses to further foam the thermoplastic polymeric members. a) forming an open structure comprising interconnected, unfoamed, thermoplastic polymeric members spaced to define openings therebetween by arranging at least a portion of the thermoplastic polymeric members in a repeating pattern; b) heating the thermoplastic polymeric members to a first temperature to soften the thermoplastic polymeric members and infusing the softened thermoplastic polymeric members with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic polymeric members without causing collapse of the structure; c) reducing the pressure to a second pressure below the first pressure while the thermoplastic polymeric members remain softened to at least partially foam the thermoplastic polymeric members; and characterized in that the method further comprises the steps of: d) heating the at least partially foamed, thermoplastic polymeric members to a second temperature below a temperature at which the structure collapses to soften the thermoplastic polymeric members and infusing the softened thermoplastic polymeric members with a second at least one inert gas at a third pressure that is sufficient to cause the second at least one inert gas to permeate into the softened thermoplastic polymeric members; and e) reducing the pressure to a fourth pressure below the third pressure while the thermoplastic polymeric members are softened and at a temperature below a temperature at which the structure collapses to further foam the thermoplastic polymeric members. d) heating the at least partially foamed, thermoplastic polymeric members to a second temperature below a temperature at which the structure collapses to soften the thermoplastic polymeric members and infusing the softened thermoplastic polymeric members with a second at least one inert gas at a third pressure that is sufficient to cause the second at least one inert gas to permeate into the softened thermoplastic polymeric members; and e) reducing the pressure to a fourth pressure below the third pressure while the thermoplastic polymeric members are softened and at a temperature below a temperature at which the structure collapses to further foam the thermoplastic polymeric members.