Profiling steps using a VISU PMM Example
Define the printer profile
- Open Calibrator and select Create pmm icon.
- Select the printer for which you wish to create a profile and click New.
- Set media name, new or existing.
- Click Next.
- In the Print mode setting step set the driver settings you want to use for this media/printer setup, and reference this in the naming. This will include ink set, resolution and speed.
- Click Next.
- If desired: Give an extra optional comment for the profile in the bottom text box.
- Click Next.
Ink Restriction: Printer linearization
Measuring the linearization chart
- Ensure that every chart fit the media by specifying the Media dimensions in the RIP and checking the ‘Settings’ button (between the Print and Measuring Device buttons).
- Click Print to produce the linearization target. PrintFactory starts a print job named ‘Linearization Test Chart’ directly from the Calibrator. The resulting linearization target contains one 18-patch step wedge for each channel/print head. It is important that the machine outputs this chart and all subsequent charts in the same way as the live jobs are to be produced. This will optimise the results of the production.
- Allow at least 15-30 minutes for the linearization target to dry unless the chart is obviously too wet.
- Check the linearization target and make sure that it does not contain any patches which are: • Too wet to measure • Dry, but too thick (too wet on application) • Non-uniform in gloss • Mottled • Sticky • Swollen If the target shows any of these above-mentioned symptoms, you will have to cut off patches and reprint it to be able to take accurate measurements. You are most likely to observe these symptoms when printing on plastic media or with ultraviolet-resistant inks, but they can also occur in other situations.
- If necessary, use the cutter tool and click the patches which are too wet or too solid. PrintFactory marks patches selected for cropping with an X, and does not allow you to skip over adjacent patches. After cutting, you need to reprint the linear file.
- Click Measure to allow the measure the spectrophotometer to collect the data from the dry linearization target
• Before you start measuring, the window shows the linearization target as gray. Each step wedge transforms into color patches as you measure the printed chart. • Import/Export buttons: You can import or export measure data in *.csv format. It is advised to save each measured chart during the processes as this data may be needed again, especially if there is a software error.
- Click Next.
Color Gamut Adjustment
If required the Gamut can be reduced to match a specific reference gamut or profile, which may not be achievable automatically.
Depending on the light colors utilised some ink splitting may be required instead of the default splits.
To evaluate the effects of the proposed ink limits and linearization on the behaviour of the target printer setup/media combination.
The ink bleeding chart demonstrates ink usage as limited by the previous steps in this procedure. Visual examination is the basis for further limiting ink usage.
Proceed as follows:
- Click Print to produce the ink bleeding chart. PrintFactory starts a print job named ‘Ink bleeding’ directly from the Calibrator.
- Examine the ink bleeding chart immediately, without waiting for it to dry. Study the patches from right to left (more ink to less ink), paying particular attention to identify physical problems.
Single ink limit:
Judging the target from right to left, look for uniformity issues, bleed, mottling, matting effects and other visual artifacts. When detected check the name of the primary inks associated with the lines that show problems and limit the ink in the linearization phase (in the beginning of the procedure).
Total ink limit:
Judge from right to left until the patches show no physical problems like drying, smudging, uniformity issues, bleeding, mottling, matting effects etc. then check the % to fill in in the Wizard.
- Identify the first patches at which the above problems do not occur anymore.
- Enter the value of this column for the ink limit.
- Click Next.
Here it is possible to chose a different module to generate the calibration test chart. Any CGATS (Committee for Graphic Arts Technology Standard) application can be utilised as the 3rd Party Module. The PrintFactory Calibrator Module allows for a selection of test charts to be used, this will be dependent on your required production.
Printer Colour Space: Printer Colour Test Charts
- Print the charts from the next window in the Calibrator ‘Printer Colour Test Charts’.
- Measure the four target charts matching the sheet number to the printed items.
- Finish the PMM. The profile will then generate and be added to the Calibrator profile list, this may take several minutes.
At the end of the calibration process a summary page provides following feedback:
- Printer name
- Media name
- Mode name
- Name of the profile in the Operating System
- Creation date
- Internal delta E: gives an idea on the internal quality of the reference profile
- Delta E calculated against the reference profile: gives an idea of whether the printer/media combinations gamut is sufficient to print to the reference profile (important for Standardized printing and proofing).