Method of forming a plate including providing a sheet of polyethylene terephthalate foam and thermoforming the polyethylene terephthalate foam into a plate. The plate comprising a bottom wall having an outer perimeter, an upper surface, and a lower support surface defining a horizontal reference plane. The plate further comprising a sidewall extending upwardly and outwardly from the outer perimeter at an angle “a” of between about 30° to about 35° relative to a vertical axis perpendicular to the horizontal reference plane. The plate further including a rim extending laterally outwardly from an upper edge of the sidewall and a turndown flange extending downwardly from an outer edge of the rim and terminating at a free end.