A printing machine has at least one machine element which can be adjusted
by the use of a setting element. An adjustment of the one machine element
has an effect on the quality of the printing performed by the printing
machine. An optical detection device, which includes a sensor that is
oriented toward the surface of a material which is being printed, detects
the quality of the printing. A controlling device receives data from the
optical sensor and adjusts, together with the setting element, the at
least one machine element based on a difference between a quality of the
printing which has been specified as a set value and the quality of the
printing detected as an actual value by the optical detection device.
This adjustment is done to manage the differences between the set value
and the actual value. The control is based on the fact that the quality
of the printing is detected in its entirety by the optical detection
device and the data is evaluated with regard to disturbing influences
acting upon the quality of the printing.