A replaceable ink cartridge can be inserted into and removed from a bubble jet printer receptacle for removably mounting the cartridge. The cartridge when mounted will cooperate with a hollow needle for supplying liquid ink to a print head and a pipe for removing waste ink from the head. The cartridge includes a container, a liquid ink reservoir and an absorber for waste liquid ink in the container, an outlet and an opening on the front wall of the container, and a label secured to the top wall of the container. The label contains a surface wiring resistance pattern including contact portions which are spaced apart and have an electric connection between them. When the container is mounted in the receptacle, the needle enters the outlet to connect the ink reservoir to the head, and the absorber enters a waste ink pipe opening. The contact portions then make sliding contact with spaced-apart electric terminals in the printer, connecting the terminals and thereby activating a control circuit in the printer.