HP Designjet 4020 and 4520 Printer Series - User's Guide: English

NOTE: This option only applies to HP-GL/2 and HP RTL prints and it is designed to improve
medium to low density gray area fills.
Visual gray calibration
This calibration will be optimized for the Image Quality options that are selected in the front panel at the
time the calibration is done.
1. It is important to select from the front panel menu the image quality settings you normally use.
Select the
icon, then Default Printing Options > Image quality.
Select print quality: (Best, Normal, Fast).
Select optimize for: (Drawings/text, Images).
Enable maximum detail: (On, Off).
2. Make sure that the paper loaded is the paper on which you want to print the neutral gray.
3. Print the first pattern to select the best gray, go to the front panel, select the
icon, then
Printhead > Visual gray calibration > Print first pattern.
4. The pattern will contain a set of images printed with different corrections of CMYK, if one of these
patterns provides the desired gray neutrality go to step 6, if there is not an exact match, choose
the number of the pattern closest to the desired gray neutrality.
5. Print the second pattern that you select from the previous step, identify the closest pattern to the
gray neutrality you want:
Print pattern 1
Print pattern 2
Print pattern 3
Print pattern 4
Print pattern 5
Print pattern 6
Print pattern 7
6. Enable the calibration: Select the
icon, then Printhead > Visual gray calibration > Enable
calibration.
7. Enter the CMYK values printed on the selected pattern into in the front panel menu: Select the
icon, then Printhead > Visual gray calibration > Select Pattern.
Some cautionary notes
When using the above procedure bear in mind the following information:
The process applies the CMYK correction to all paper types loaded, and to all image quality
settings, but it can guarantee gray neutrality only for the paper type and front-panel print-quality
settings that were used while doing the calibration. The calibration should be run again with any
other print-quality settings and paper types that you might use (one calibration per print-quality
settings + paper).
If you change the printheads, you should recalibrate.
When selecting the different gray patterns, make sure that you use the lighting conditions in which
you want the final image to be viewed, fluorescent light or sunlight for example.
160 Chapter 15 The problem is... (print quality topics) ENWW
Print quality problems