The surface of the steel cliché plate is initially coated with a light-sensitive material. Before exposing the plate to light, a film containing the desired image is placed face down on it.
The film and plate are then exposed to light. The light hardens the area of the plate not covered by the film.
The areas that were covered by the film remain soft. The soft area of the plate is then removed by soaking it in a developer bath.
The area containing the image leaves an impression that will be etched in a bath consisting of nitric acid, chlorine (III), iron, or similar chemicals.
The actual etch depths for a steel plate varies depending on its intended use. In general, the etch depths are 16 microns for fine scripts, and 22 microns for standard scripts.