Vertical banding is sometimes a problem when using HP Coated Paper. It is visible on gray areas printed on true black and on areas with light combinations of cyan and magenta printed on color.
This vertical banding is the result of printhead-to-paper spacing variations caused by cockle.
To avoid vertical banding, try the following solutions:
-
Use the new HP Coated Paper (available in C+ and D+ size) or HP Heavyweight Coated Paper (available in A/A4, B/A3).
-
Use color modes to print black areas instead of true black.