Cleaning Print Cartridges You may need to clear the print cartridge ink nozzles when dots or lines are missing from your printout. The instructions for clearing the ink nozzles on a black or color print cartridge are the same. 1. Click on the desktop printer. 2. Choose Clean Print Cartridge from the Printing menu. 3. Insert a sheet of U.S. Letter- or A4-size paper into the printer when the Ready light blinks.