Filler particles of a moisture-permeable, organic polymeric material are used in a polymeric coating composition, and this composition can be applied to a surface of a molded, fiber-reinforced polymeric material, such as sheet molding compound (SMC), to enable the electrostatic application of a layer of a powder primer to the same surface overlying the polymeric coating. And, when the molded SMC is heated to cure the powder primer layer, the out-gassing of moisture from the heated SMC does not result in defects on the surface of the molded SMC.