This recommended practice describes the physical and chemical characterization techniques for identification of epoxy adhesive and prepreg resin systems in order to verify the chemical formulation, resin B-staging, cure reaction rates, adhesive moisture content, and resin component mix ratios, as necessary to achieve manufacturing and quality producibility and engineering performance. These techniques have been developed and validated for epoxy adhesive and prepreg resin systems, but they are expected to be applicable to other thermoset materials, such as phenolics, polyimides, or polyesters.