G7 calibration is conducted between the Fiery server calibration and printing of profiling measurement patches.
G7 calibration is applied on the top of the
Fiery server calibration. Entering the G7 calibration
process, you will select the patch layout for the P2P target you wish to use, measure
them, inspect the results, and make adjustments to the settings, if needed.
The G7 specification defines standard
grayscale curves that can be used to create a common neutral appearance of output on
different printers. G7 calibration adjusts the color output of a printer to the G7
specification, using measurement data from a specific G7 target (P2P target). Fiery Color Profiler
Suite supports printing
and measuring different P2P targets that are used for G7 calibration. You can measure
with any supported measurement instrument.
-
In the Patch layout window, select the Patch set
you want to use:
- P2P51 (the newer target,
a revision of the original)
- P2P25Xa (the original
target)
- P2P51 Randomized
- P2P51 Randomized 2up
(recommended choice for cut sheet toner presses)
Note: The actual values used in
the targets are similar, but the newer version is a more precise version of
the G7 specification.
-
Click Print and measure the patch page.
-
Review the G7 gray balance measurement results.
Because this is the G7 calibration run, it is expected that the results are
failing. It is the measurements from this target that will be used to
calculate the NPDC curves necessary for G7 calibration.
The NPDC (Neutral Print Density Curve) is displayed separately for CMY
(composite) and K (black). Gray balance is plotted as a*b*. In the table,
the weighted average must be less than 1.5 to show as green. The weighted
maximum must be less than 3 to show as green.
-
(Optional) Click
Correction options to display the correction curve,
and expose advanced options applied to the formation of the correction curves.
You can choose to keep the
defaults or change them.
-
Click OK
to print the P2P patch page again with the NPDC curves applied.
-
Measure the patch pages and view the G7 results.
-
If the G7 result is passing (all
results show in green), click Next. If the result is
failing (any result highlighted in red), then click
Iterate to repeat the process. It is not uncommon
that two or three iterations must be performed to pass G7 compliance.
