Abstract: An ink container for an ink jet printer adapted to supply ink via a tube to an ink jet cartridge. The cartridge includes a bottle, a cap engaging the bottle to form an ink containing cavity, an ink exit channel from the ink containing cavity through the cap, an air inlet channel through the cap into the ink containing cavity, and an air entrance opening from the air inlet channel into the ink containing cavity. The air entrance opening has a perimeter to area ratio that is greater than 2/R where R is the equivalent radius of the air entrance opening. This perimeter to area ratio (or shape factor) allows for easy formation and break off of bubbles at the air inlet channel. If such bubbles remain attached to the air inlet opening they can prevent some of the ink in the container from flowing therefrom for printing.

Abstract: A novel method and system for calibration of paper feed in an ink jet printing system is used to remove overfeed bands and underfeed bands from an image. The method begins by feeding print media into the ink jet printing system. A color density test target is formed by simultaneously applying an on/off pattern print mask to print numerous print swaths while incrementing paper feed values. Each paper feed value corresponds respectively to each print swath. The color density test target reveals shifts from light to dark to light in order to identify a maximum optical density region. The paper feed value from the color density test target corresponding to a maximum optical density region on the color density test target is selected and entered into the printing system. The entered value calibrates printing system in order to minimize the presence of overfeed bands and underfeed bands while printing.