Ink cartridge fluid flow arrangements and methods

A printer ink cartridge, comprising:

• a housing defining an ink reservoir containing ink;
• an ink outlet positioned on a bottom side of the housing;
• and
• an air vent extending from a top side of the housing into the ink reservoir, the air vent having a first end at a top side of the housing, a second end adjacent to an internal bottom surface of the ink reservoir, and a valve positioned at the second end, the first end being open to atmospheric air conditions, the valve in air flow communication with the open first end, the valve configured to provide air flow into the ink reservoir automatically when a threshold negative pressure condition exists in the ink reservoir and prohibits ink flow into the air vent.

An ink cartridge, comprising:

• a housing including opposing top and bottom walls and a plurality of side walls that together define an ink reservoir for holding a volume of ink;
• an ink outlet positioned on the bottom wall of the housing;
• and
• an air vent arrangement including an air vent aperture formed in one of the plurality of side walls or the top wall of the housing, an air valve exposed to ink in the ink reservoir and having an air outlet in flow communication with the ink reservoir, and an air flow channel positioned along one of the side walls of the ink reservoir, the air flow channel in flow communication with the air vent aperture and the air valve, the air valve positioned adjacent the bottom wall of the housing.