AbstractThe need for composite materials with improved properties tailored to the requirements of specific end uses has led to the development of hybrids reinforcement systems in which two or more reinforcing fibers are combined in a thermosetting matrix. Polyester fibers (PET) are currently being used in combination with other fibers, particularly fiberglass, for impact strength and surface quality improvement. The use of polyester fiber in combination with glass fiber as a reinforcement for composite materials has resulted in the development of novel types of hybrid composites. This study discusses our work to achieve an optimum balance of composite properties through changes in matrix formulation, composite compounding, and processing steps. A number of these parameters are shown to have a significant effect on the performance of the composite. This work includes an analysis of thermoset polyester and epoxy resin formulations, in addition to the effect of other additives for typical BMC, SMC, and injection‐molding operations. The fiber loading, PET–glass fiber ratio, and fiber length are briefly discussed, as these are factors in determining the composite properties. These characteristics are discussed in combination with the compounding techniques. The combination of both factors were observed to have a major effect on the mechanical and surface appearance of the composite. The coherency and dispersibility of the specific PET fiber used had additional effects on resin compounding and final composite characterist