Epson SureColor T3270 Flush CartridgesCleaning Cartridges are used to ensure there is no chemical reaction or color issues between two different inks in the lines of your printer. If you are changing the ink in your printer, these cartridges act as a buffer to filter out old ink before the new ink is inserted. Remove any cartridges from the printer and insert the cleaning cartridges. Run cleaning cycles to push the cleaning solution through the lines and to the printhead.