Manual calibration is also recommended whenever you are using pre-printed media, print on the liner or if the printer will not correctly auto calibrate.
With performing this manual calibration, the printer runs extensive tests to detect and set media type and media length, and then it adjusts the media sensors for optimal performance with the installed media.
For more details on the manual calibration, click here>>
For a video showing how to perform this manual calibration, click here>>
(please note that this video is in Chinese only but the procedure can be fully seen.