A printing material delivery system includes a printing material storage that includes a printing material. The printing material deliver system also includes a print head. A pressurizing device defines a housing that includes an inlet coupled to the printing material storage, an outlet coupled to the print head, and that houses a rotatable member that is operable to rotate and create a pressure differential in order to transfer the printing material from the printing material storage, through the pressurizing device, and out of the print head.