Abstract: A device for positioning a printing head of a printer in response to recording carrier/substrate thickness includes a reflex sensor arranged in a protected space formed between a head-carrying carriage and an opposing printing head housing surface. During printer initialization or upon insertion of a recording carrier/substrate having a thickness greater than a predetermined thickness, the printing head is slightly displaced with respect to the carriage as a result of brief contact of the printing head print surface with the recording carrier that is supported on a printing abutment. The reflex sensor measures the displacement travel distance of the printing head and generates an input signal to an evaluation circuit. The evaluation circuit generates an output control signal to a carriage displacement drive in response to the measured displacement of the print head to automatically set the distance between the printing head and the recording carrier or printing abutment.