This setting adjusts the thickness of vertical lines to express fine lines and small characters more clearly. The higher the level number, the thicker the vertical lines printed.
Remark
This setting is also available when 'Line Refinement' is set to [On] in the printer driver.
With this setting, vertical lines are based on the direction in which the paper is fed.
Selecting [Level 2] or higher for this setting may result in abrupt changes in gradation with halftone images.