Abstract: A metal seat pan is placed inside a rotational casting mold to define part of a rotational casting cavity into which is introduced rotationally castable material for forming a flexible plastic seat cover. A rotational casting operation produces a closed, hollow seat cushion shell defined by the seat pan and the flexible plastic cover. Foaming ingredients are introduced into the hollow shell to form a resilient foamed plastic interior. The resulting seat cushion is monolithic, without seams or joints and has no removable parts or mechanically joined components which will come apart from each other.