Abstract: A process for forming a metal or metal compound coating on a face of a hot vitreous substrate in sheet or ribbon form by continuously advancing the substrate in a downstream direction along a path through a coating station which discharging droplets of liquid coating precursor material in the downstream direction so that such material contacts the substrate at the coating station and continuously withdrawing vapors thereafter from the coating station in the downstream direction an annealing the substrate is characterized in that the hot coated substrate (1) passes from the coating station (3) to an annealing lehr (6) via a re-heating station (4) at which sufficient radiant heat energy is supplied to the hot coated substrate (1) to raise the temperature or the mean temperature of its coated surface at the re-heating station (4) through a certain temperature range, at least the upper end of such range being not less than a temperature 100.degree. C.