A sandwich ink-jet print head constructed in planar technology is welded into a dual in-line plug-in package which has on its top side a receiving opening for the sandwich ink-jet head and on its underside a contacting and balancing opening which can be sealed so as to be tight with respect to ink, as well as an ink inlet orifice for supplying the printing fluid. After insertion of the sandwich ink-jet head into the dual in-line package, the sandwich ink-jet head is electrically balanced via the contacting and balancing opening, to be precise by means of a resistor array arranged on the sandwich ink-jet head. As a result of the arrangement in a dual in-line package, the ink-jet print head can be mounted so as to be exchangeable in a mounting on the printer carriage. The ink-jet print head is connected to the ink supply system of the printer via a resilient adaptor.