The use of dual-elastomeric materials for minimizing the level of extrusion in a thicksection seal is examined. A thick-walled cylindrical seal made from a combination of conventional carbon-black-reinforced elastomer and a bre-reinforced elastomer is considered. The deformation of the seal and the evolution of the contact pressure are determined by a combination of experimental test and detailed non-linear nite element analysis. The results show that the level of extrusion in the dualelastomer seal is signi cantly less than that in conventional single-elastomer seals. The implications of the results for the design of packing elements used in the oil and gas industry are discussed.