A forming method of spacers in a flat panel display is provided. A plurality of U-nut fasteners can be engaged one with another to form a collated strip of fasteners. The maintenance station provides: a capping mode for capping a nozzle of the printing head; a wiping mode for wiping the nozzle of the printing head; and an ink spitting mode for preventing clogging of the nozzle of the printing head, and also the maintenance station includes a waste ink collecting bath for collecting ink discharged during the ink spitting mode. The significance of contact surfaces between the two rings allows a damping of vibrations during operation.