Many epoxy resins have been introduced during the last several years as replacements for Epon 812 since the Shell Chemical Company discontinued production of this popular embedding resin. In a past study, the present investigators examined several of the “replacement” resins for physical characteristics such as viscosity, flow rate, density, mass weight, and hardness of the polymerized medium. In addition, other equally important parameters including sectioning and infiltrating character as well as stain-ability and section strength subsequent to beam and vacuum conditions also were evaluated. The present work follows a similar rationale and seeks to determine this same information for Eponate 12, an epoxy resin designated as a true generic replacement for the formerly available Epon 812 product.For purposes of physical comparisons, Eponate 12 was tested against a sample of original Shell Epon 812 still maintained in our laboratory.