Abstract While rapid strides have been made in the synthetic organic chemistry of rubberlike materials and in the elucidation of relationships between structure and mechanical properties of elastomers, it is generally not feasible by synthesis alone to construct a rubbery type of polymeric structure which is likely to fulfill all requirements for a given specific application. The tolerances imposed by synthetic methods are very close, and experience indicates that comparatively slight changes in reaction conditions, or monomer, soap, and catalyst concentrations, all may have a profound effect on the balance of properties desired. To aid in the achievement of desired properties, recourse is generally had to compounding. Thus, elastomers are compounded for a variety of reasons. For example, plasticizers are added for improved low-temperature properties, reinforcing agents for improved tensile, tear, and abrasion properties, vulcanizing ingredients for reduced plastic flow and improved elastic recovery, and antioxidants for providing resistance to aging. Furthermore, while optimum combination of synthesis and compounding efforts may achieve adequate bulk properties, the stock may still fail because of surface difficulties, e.g., permanent discoloration on contact with stains, and surface tack development. To overcome these difficulties, in some instances successful use has been made of surface coatings such as talc, waxes, or thin, adherent polymeric films.