A method and apparatus for applying an image to a printing plate while maintaining registration between the image and a reference edge of the printing plate include mounting the printing plate on a plate making machine and then determining the locations of two or more points on the reference edge. 01% to 10% by weight of a hair styling polymer comprising one or more hydrophobic groups, from 0. A fluid supply unit comprises one impulse valve that serves to release an essentially constant volume flow, acted upon by an impulse valve control device which is constructed such that the fluid volume flow released by the fluid supply unit and flowing into the emitter-receiver system does not exceed a limiting volume flow QK.