composition comprising susceptors having the capability of absorbing microwave energy , said susceptors comprising a particulate substrate substantially non - reflective of microwave energy and a coating capable of absorbing microwave energy , and a matrix substantially non - reflective of microwave energy . susceptors are typically particles having a thin - film coating thereon . the matrix typically comprises polymeric or ceramic materials that are stable at temperatures conventionally used in microwave cooking . the composition allows reuse of the susceptors , eliminates decline in heating rate , eliminates arcing , allows the heating rate to be controlled , allows overheating to be controlled , and allows formation of microwave heatable composite materials having very low metal content .