Abstract: Provided are a method and apparatus for optimally adjusting a printing press having multiple printing units. In one example, for each printing unit, relative positions are calculated between an anilox roll and a form cylinder that form a first cylinder pair and between the form cylinder and an impression cylinder that form a second cylinder pair. Calculations based on colour selective detection of printing marks are performed to identify adjustment parameters for the relative positions of the first and second cylinder pairs, and one or more of the relative positions are adjusted.