Method to operate a printer given exchange of a reservoir

A printer to print to a printing substrate, comprising:

• a mixer to mix toner concentrate extracted from a toner concentration reservoir and carrier fluid extracted from a carrier fluid reservoir into a developer mixture;
• a developer station comprising an application unit and a developer roller, the developer mixture being applied directly or indirectly onto the developer roller via the application unit and with assistance of an electrical field;
• and
• a control unit that modifies a strength of the electrical field given an exchange of at least one of the toner concentrate reservoir and the carrier fluid reservoir such that a predetermined desired inking of the printing substrate is maintained even given a change of the toner concentration that is due to the exchange of at least one of the toner concentrate reservoir and the carrier fluid reservoir.

A printer to print to a printing substrate, comprising:

• a mixer to mix toner concentrate extracted from a toner concentration reservoir and carrier fluid extracted from a carrier fluid reservoir into a developer mixture;
• a developer station comprising an application unit and a developer roller, the developer mixture being applied onto the developer roller via the application unit and with assistance of an electrical field;
• and
• a control unit that modifies a strength of the electrical field given an exchange of at least one of the toner concentrate reservoir and the carrier fluid reservoir such that a predetermined desired inking of the printing substrate is maintained even given a change of the toner concentration.