An apparatus for coating a donor surface that is movable relative to the apparatus with a layer of metallic particles or particles having a metal-like appearance and reflectivity, the particles adhering more strongly to the surface than to one another. The apparatus comprises an application device to apply to the donor surface a fluid stream within which the particles are suspended, a housing surrounds the application device forming an interior plenum for confining the fluid stream, the housing prevents egress of particles from a sealing gap defined between the rim of the housing and the surface to be coated, and a suction source connected to the housing to extract from the plenum excess fluid and particles. In operation, the suction source extracts substantially all particles that are not in direct contact with the donor surface, leaving substantially a single particle layer adhering to the donor surface upon exiting the apparatus.