Abstract: A process for forming a coating on a conductive substrate, which comprises establishing a fluidized bed of a powder coating composition, in which the mechanism for particle charging is tribostatic charging immersing the substrate wholly or partly within the said fluidized bed, applying a voltage to the substrate for at least part of the period of immersion, whereby particles of the powder coating composition adhere to the substrate, withdrawing the substrate from the fluidized bed and forming the adherent particles into a continuous coating over at least part of the substrate. The process enables the coating of substrate areas which, because of the Faraday cage effect, are inaccessible in conventional electrostatic coating processes, and also enables the formation of thinner coatings than are obtainable by conventional fluidized-bed processes.