If you still see white or dark lines or missing colors in your printouts, even after cleaning the print head several times, you can flush the ink tubes.
Flushing the ink tubes replaces all the ink inside the tubes, so flush the ink only if you cannot improve print quality by cleaning the print head several times.
Flushing the ink tubes affects the service life of the ink pads by causing them to reach their capacity sooner. When you see an error message indicating that an ink pad is nearing the end of its service life, the product stops printing and you must contact Epson for support.