Abstract: A device and method for automatically replenishing ink to an ink cartridge is described. A supply ink reservoir is connected via a tubing device to a print ink container in the ink cartridge. The supply ink reservoir supplies ink to the cartridge while ink is being printed out of the print head of the cartridge. In one described embodiment, the supply ink reservoir is part of an ink container bottle that also includes a replenishing ink reservoir positioned above the supply ink reservoir. The replenishing and supply ink reservoirs communicate with each other through a passage which is controlled by a floating valve mechanism positioned within the supply ink reservoir. Thus, the floating valve mechanism is arranged to control the fluid level in supply ink reservoir at a substantially constant level. Thus, the print ink container is feed at a substantially constant pressure head, which facilitates good quality printing.