or cardboard substrate 2 to this end a conveying device is provided which in the illustrated example includes rollers 11 over which the substrate 2 is moved along a direction of travel 13 contacting at the side 22 past a coating unit 5 in the form of a coating group the coating unit 5 applies a film 7 composed of initially still fluid coating material in the form of a uv curable coating controlled by a computer 15 the coating unit 5 operates according to the drop on demand principle wherein the nozzles 51 of the coating unit 5 eject individual droplets onto the substrate surface 21 to be coated in response to control signals from the computer 15 and the droplets form a preferably continuous film the nozzles 51 are arranged in a row transverse to the direction of travel wherein the row spans at least u00be of the width preferably the entire width of the substrate 2 to allow high coating speeds to be achieved a system of nozzles 51 is preferably used which for the coating is rigidly mounted in the direction transverse to the direction of travel in a departure from the illustration in fig1 multiple rows of.