An ink cartridge includes a frame having an opening formed therethrough, and at least one film connected to the frame. The frame and the at least one film define an ink chamber therein. The film comprises a first portion, a second portion, and a third portion, and the second portion is positioned between the first portion and the third portion, and the first portion and the third portion are raised with respect to the second portion. A line intersecting a peak of a first end of the first portion and a peak of a second end of the first portion is slanted with respect to a center line of the opening, and a line intersecting a peak of a first end of the third portion and a peak of a second end of the third portion is slanted with respect to the center line of the opening.