Different cylinder head gasket materials are in use today, primarily due to the elimination of the standard asbestos millboard, new engine designs, requirements on compressed thickness, and increasing durability and sealing standards. The history of small engine cylinder head gaskets is reviewed. Current and future head gasket requirements and gasket material and types are outlined. The affect of these materials on heat transfer is summarized. Design considerations directed to attaining and maintaining clamp loads and clamp load loss are addressed. Static and dynamic testing to improve and verify the suitability of designs is explained. A smooth transition from a tested prototype to production product requires attention to clamp load related details.