Abstract: Apparatus for dampening a printing press comprises a spray bar (26) with solenoid operated nozzles (29) for dispensing a dampening fluid to the press, a controller (30) that sets the flow rate of the dampening fluid to the press through the nozzles, and workstation (31) operable to drive the controller (30). The nozzles (29) are to set an initial flow rate for the commencement of a print run, corresponding to an initial setting value (IS) dependent on a default value (D) and a stored value (AVOFS) derived during at least one preceding print run, and then the setting is updated during the print run by updated data (AS) corresponding to an updated flow rate for the commenced print run. An offset value (OFS) is then calculated based on the difference between (IS) and (AS). The stored value (AVOFS) is then calculated based on a running average of (OFS) for successive print runs.