An ink cartridge includes a frame, a first wall comprising a film connected to the frame, and a second wall opposite the first wall. The frame, the first wall, and the second wall define an ink chamber therein, and the ink chamber is configured to store ink therein. The ink cartridge also includes a movable member positioned within the ink chamber, and a shaft extending between the first wall and the second wall. The movable member is configured to pivot about the shaft. Moreover, the frame includes a first material, and the shaft includes a second material which is different than the first material. A rigidity of the second material is greater than a rigidity for the first material.