A method of mounting printing plates (26, 28, 30, 34, 36, 38) on a plurality of cylinders for multi-colour printing, comprising the steps of: a) determining, for each colour, a number of printing plates to be mounted on a corresponding cylinder, b) specifying coordinate positions for at least two reference structures (32; 32'; 72, 74) on each printing plate, c) forming the reference structures at the specified coordinate positions on the printing plates, d) installing one of the cylinders in a mounter having two cameras, e) adjusting the cameras in a first direction to the specified coordinate positions for one of the printing plates and mounting the printing plate on the cylinder in a position where each reference structure (32; 32'; 72, 74) is included in an image captured by one of the two cameras and is aligned with a target mark (70; 72', 74') that corresponds to the specified coordinate position, f) repeating step (e) for each printing plate to be mounted on the cylinder, and h) repeating steps (d) to (f) for each cylinder, characterized in that it comprises the further steps of: - providing a reference mark on each cylinder, and - determining a positional relationship between the reference mark and the coordinate positions of the reference structures, and in that - in step e), the positions of the cameras relative to the cylinder are adjusted also in a second direction orthogonal to said first direction by controlling a drive motor to rotate the cylinder in the mounter in accordance with the positional relationship between the reference mark and the coordinate positions or by rotating the cameras relative to the cylinder independently of one an other in accordance with the positional relationship between the reference mark and the coordinate positions. a) determining, for each colour, a number of printing plates to be mounted on a corresponding cylinder, b) specifying coordinate positions for at least two reference structures (32; 32'; 72, 74) on each printing plate, c) forming the reference structures at the specified coordinate positions on the printing plates, d) installing one of the cylinders in a mounter having two cameras, e) adjusting the cameras in a first direction to the specified coordinate positions for one of the printing plates and mounting the printing plate on the cylinder in a position where each reference structure (32; 32'; 72, 74) is included in an image captured by one of the two cameras and is aligned with a target mark (70; 72', 74') that corresponds to the specified coordinate position, f) repeating step (e) for each printing plate to be mounted on the cylinder, and h) repeating steps (d) to (f) for each cylinder, - providing a reference mark on each cylinder, and - determining a positional relationship between the reference mark and the coordinate positions of the reference structures, and in that - in step e), the positions of the cameras relative to the cylinder are adjusted also in a second direction orthogonal to said first direction by controlling a drive motor to rotate the cylinder in the mounter in accordance with the positional relationship between the reference mark and the coordinate positions or by rotating the cameras relative to the cylinder independently of one an other in accordance with the positional relationship between the reference mark and the coordinate positions.