When Bidirectional Printing (the Print-head Prints in Both Directions) Produces Misaligned Verticals or Blurred Colors
Perform the Auto Adjust Head Position.
Or, set unidirectional printing (the printer head prints in only one direction).
Unidirectional printing moves the printer head in only one direction. This option is effective when the print quality is inconsistent, or rule lines are printed unevenly or are poorly spaced.
Unidirectional printing is slower but produces better print quality than bidirectional printing.