The printout is too light or too dark.
Fine lines and characters with a small point size are light.
The toner density settings are not correct.
Adjust the toner density and print the data again. (See "Density.")
'Toner Save' is set to [On].
Set 'Toner Save' to [Off] in the printer driver and print the data again. (See the Help function on the printer driver.)
The specified thin lines and fine characters cannot be processed properly.
Set 'Resolution' to [600 dpi] and print the data again.
Set 'Line Refinement' to [On] and print the data again.
Set a higher level number for 'Horizontal/Vertical Line Refinement' and print the data again. (See "Horizontal Line Refinement," and "Vertical Line Refinement.")