An ink containment system for an inkjet cartridge, for storing ink for printing, comprises a rigid basin member and a rigid moveable plate. A flexible membrane is affixed to a surface of the basin member and to a surface of the plate forming an ink reservoir within the basin member, plate and flexible membrane. A spring-biased mechanism is disposed between the basin member and plate, for biasing the plate apart from the basin member, generating a negative pressure within the ink reservoir and the basin member remaining stationary relative to the movement of the plate. The basin member has a bowl-like configuration and the spring is seated within the reservoir in such a way that when the ink reservoir has collapsed due to depletion of ink, the flexible membrane and moveable plate are substantially flush with surfaces of the basin member.