During bidirectional (or high speed) printing, the print head prints while moving in both directions, and vertical lines may be misaligned. If print quality does not improve, disable the bidirectional (or high speed) setting. Disabling this setting may slow down printing speed.
Windows
Clear High Speed on the printer driver’s More Options tab.
Mac OS
Select System Preferences from the menu > Printers & Scanners (or Print & Scan, Print & Fax), and then select the printer. Click Options & Supplies > Options (or Driver). Select Off as the High Speed Printing setting.