An ink containment system for an inkjet cartridge, for storing ink for printing, comprises a housing having a plurality of walls. A rigid basin member and a rigid moveable plate are disposed within the housing. 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.