The sequence and mode of combination of elastomer blend components was found to affect the crosslinking processes occurring on vulcanization and the vulcanizate structure. The polymer medium affected network nonuniformity, which was higher in a polar rubber medium. Premixes used rendered migration of crosslinkers difficult; diffusion of active complex, esp. ZnO, appeared unlikely to occur. Traditional seasoning of rubber mixes should help equalize the concentration of auxiliaries in the polymer bulk.