Caution: Never shake, drop or hit cartridges against the palm of your hand or any other hard surface. Shaking the print cartridge does not mix ink and hitting cartridges against a hard surface does not clear the nozzles. These actions hurt print quality because they allow bubbles to form near the ink firing chambers. These bubbles prevent the nozzles from firing, causing white streaks in print image.
UPDATED: October 27, 2020