Conductive coating (20) is produced by the process of first mixing by high shear mixing a mixture of 0.03 parts per weight of carbon black together with 0.003 to 0.01 parts per weight of wetting agent and 20 parts of solvent, and further mixing in by low shear mixing 1/2 to 1 part per weight of thermosetting resin. Prior to application this is then sprayed into place on the substrate. In this particular case, the substrate is exterior face sheet (12) of honeycomb structure (10) which may serve as part of a spacecraft, to electrically conduct away surface charges.