Canon IMAGERUNNER C2550 Printer Manual page 241

Fine lines and characters with a small point size are light.
Cause The specified thin lines and fine characters cannot be processed properly.
Remedy 1 If 'Resolution' in the printer driver is set to [1200 dpi], press [Dark] to adjust the
density with 'Density Fine Adjustment', and print the data again.
NOTE
You can also perform the same procedure from the touch panel display. (See "Density
Fine Adjustment," on p. 3-18.)
Remedy 2 Set 'Resolution' in the printer driver to [600 dpi] and print the data again.
NOTE
You can also perform the same procedure from the touch panel display. (See
"Resolution," on p. 3-18.)
Surface roughness, unevenness, or streaks in image and graphics portions are visible.
Cause Combination with halftone patterns may cause the problem.
Remedy 1 Set [Objective] in the UFR II printer driver or PCL printer driver to [Photos] or
[Graphics] and perform printing again.
Remedy 2 Set [Halftones] in the printer driver to [Pattern 6] and perform printing again.
(See the Help function on the printer driver.)
NOTE
You can also perform the same procedure from 'Halftones' in the touch panel display. To
perform the procedure, apply the halftone pattern setting separately for the following
kinds of data. (See "Halftones," on p. 3-46, p. 3-59, p. 3-75, p. 3-96.)
- Text : Resolution
- Graphics : Gradation
- Image : Gradation
6-25
Printing Problems
6