The invention relates to a surface printing press with a printed image carrier having an image thereon corresponding to the matter to be printed on paper or the like. The image on the printed image carrier is in the form of hydrophilic and hydrophobic areas. In order to be able to modify the extents and positions of these areas on the press directly and thus reduce press idle times the printed image carrier is made of a material such as polymer whose said areas may be changed over dotwise between the said hydrophilic and hydrophobic conditions by electrical effects taking place in an electrochemical process with one electrode being formed by the plate cylinder and the counter-electrode being formed by a roller bearinged for rotation in an electrolyte container. One of the two electrodes is in the form of matrix and is operated so as to produce a pattern of dots.
