KB223225802: How to implement an M1 based printing standard

Description

Printing standards like the ISO 12647-2 provide target Lab values for the primary (solids), secondary and overprint colors but also for the paper color. How these colors are measured is described in the ISO document by specifying the measurement condition.

• ISO 12647-2:2007 measurement specification: D50 / 2° observer / 0/45 or 45/0 geometry / black backing
• ISO 12647-2:2013 measurement specification: D50 / 2° observer / 0/45 or 45/0 geometry / black backing / M1

ICC profiles which represent a certain printing condition of a printing standard contains these measurement condition information.

For the sake of measurement consistency, it is important to use the same measurement condition as specified in the ISO printing standard when working according to a specific printing standard!

XRGA

Which  brand of measurement device you use is not important, but if you use an old X-Rite or GretagMacbeth device, you should take care that the calibration is done according to the XRGA standard. (https://www.xrite.com/blog/xrite-graphic-arts-standard). All measurements are XRGA compliant when using Kaleidoscope 12.1 or higher!

ISO 13655:2009

A measurement condition of a device can be described by specifying the light source (D50), the observer angle and the geometry. You would think that if two spectrophotometers of a different brand claim to have the same measurement condition, they also return the same readings, but that is/ was not necessarily true. Because of the different D50 light source "technology" and the different amount of UV in the light source, you can have a different reading. To deal with this issue, a standard was developed describing the light source properties and four measurement conditions.

• M0: CIE Illuminant A (undefined UV amount)
• M1: CIE Illuminant D50 (fixed UV amount)
• M2: UV cut
• M3: Polarization filter with UV cut

M1 based printing standards

A trend in the production of press papers is that they contain more OBA's to let the paper appear more white. Because of this change, the printing standards become outdated and difficult to match/ use as a printing standard. Hence, new printing standards were published supporting the high amount of OBA's press papers. At the same time, the M1 measurement condition was adopted as mandatory to use. Only when using M1 one can measure and deal in a consistent way with OBA's!

This KB article describes how Esko products can be used for the implementation of the ISO 12647-2:2013 printing standard which is M1 based.

Procedure

Curve Run - the process of creating a dot gain compensation curve with PressSync 18.0

PressSync 18.0.1 and older don't support any measurement conditions other then M0!

For the calculation of compensation curves it is not critical to measure in M1. The difference between M1 and M0 is mainly in the highlights and negligible.

Nevertheless, here is a workaround to measure the P2P25 or P2P51 chart in M1 with i1Profiler:
i1Profiler download link: https://www.xrite.com/service-support/product-support/formulation-and-qc-software/i1Profiler

1. At the Home page, select a CMYK printer and click Measure Reference Chart.
   
   
   
2. Download this file P2P25Xa (i1Pro-i1iO).rwxf or P2P51 (i1Pro-i1iO).rwxf.
3. Right click Saved Workflows and choose Open Containing Folder in the contextual menu.
   
4. Copy the "P2P25Xa (i1Pro-i1iO).rwxf" or "P2P51 (i1Pro-i1iO).rwxf" file to the MeasureReferenceWorkflows folder.
5. Refresh the Assets panel by clicking the circular arrow button in the right corner of the Assets panel title bar.
6. Double click the "P2P25Xa (i1Pro-i1iO).rwxf" or "P2P51 (i1Pro-i1iO).rwxf" file in the Assets overview.
7. Select the correct spectro and click Next.
8. Select Dual scan as the Measurement mode.
   
9. Click the Measure button to start the measurement session.
10. Once measured, click the Save button.
11. Choose i1Profiler CGATS Custom as the file type with the following selection:
    
12. Open your PressSync curve set and load the text file via Measure > Load Measured Data (CGATS).

Due to a bug in i1Profiler, no rwxf file can be used for the Equinox_CMYK_OGB and Equinox_OGB chart. Please follow these steps:

1. At the home view, select a CMYK + 3 Printer if you want to measure the Equinox_CMYK_OGB chart or a CMYK + 2 Printer for the Equinox_OGB chart.
2. Click the Profiling workflow and define the Lab value for the extra inks (if you don't do this, the reference color in the measure module will not be correct).
   
   Orange= 69.5 / 51.6 / 80.5 ~ Green= 60.5 / -75.6 / 35.4 ~ Blue= 19.7 / 38.1 / -77.6 ~ Violet= 23.98 / 47.1 / -65.5
3. Click the Home button and select the Measure Reference Chart workflow.
4. Select the correct Spectro at the Define Chart step.
5. Click the Load button and use this file EquinoxChart_CMYK_OGB.txt or this one EquinoxChart_OGB.txt.
6. Select the Measurement step and measure the chart.
7. Click the Save button when finished with measuring the chart.
8. Choose i1Profiler CGATS Custom as the file type (see step 11 of the procedure to measure the P2P25 chart for the settings).
9. Open your PressSync curve set and load the txt file via Measure > Load Measured Data (CGATS).

Profile Run - the process of creating a press profile with Color Pilot 18.0

Color Pilot 18.0 does only support M1 in patch mode and in some cases in scan mode. This KB article gives an overview:

• Page:
  KB184715097: Which measurement conditions are supported by Color Engine Pilot and Color Pilot

One can however choose between two workarounds, one using Color Pilot and one using i1Profiler.

Color Pilot workaround

Workaround to measure in scan mode with either the i1Pro2 or i1iO2:

1. Copy the desired (you have to choose between i1 or i1io) pressinfo.dat (after extracting it) to this folder: \\localhost\bg_data_cms_v010\w\dfe
   1. pressinfo - i1.7z
   2. pressinfo_i1io.7z

2. Open the dat file and define the inkset you want to use:

   <CMSInfo type="group">
     <CMSID type="int" value="0"/>
   <inkset type="int" value="2"/>
   
   0= CMYK
   
   1= CMY
   
   2= CMYK Red
   
   3= CMYK Orange
   
   4= CMYK Green
   
   5= CMYK Blue
   
   6= CMYK Violet
   
   7= CMYK Red Green
   
   8= CMYK Reg Blue
   
   9= CMYK Red Violet
   
   10= CMYK Orange Green
   
   11= CMYK Orange Blue
   
   12= CMYK Orange Violet
   
   13= CMYK Green Blue
   
   14= CMYK Green Violet
   
   15= CMYK Red Green Blue
   
   16= CMYK Red Green Violet
   
   17= CMYK Orange Green Blue
   
   18= CMYK Orange Green Violet

3. Start Color Pilot 16.x or newer.
4. Switch to the M1 measurement mode in the status bar (bottom right corner) or Preferences.
5. Click the Digital Presses icon.
6. Click Set Profile.
   
7. Create a new profile.
8. Define your layout choice:
   
9. Export the PDF files and print the PDF files.
10. Click Next to start the measurement procedure.
11. At the end of the process, you can repair the data:
    
    
    
12. Click Next twice.
13. Uncheck Create color strategies.
14. Click Next.
15. Click Finish.

i1Profiler workaround

Workaround to measure in scan mode with either the i1Pro2 or i1iO2:
i1Profiler download link: https://www.xrite.com/service-support/product-support/formulation-and-qc-software/i1Profiler

1. At the home page, click Profiling:
   
2. Double click a desired patch set.
   
3. Click the Test Chart button at the bottom.
   
4. Select the correct spectro and choose Dual Scan as Measurement Mode.
   
5. Click the Save As… button below the layout to save the layout as a PDF.
6. Rip and print the layout.
7. Come back to i1Profiler and click the Measurement button at the bottom.
8. Measure the charts.
   
9. Click Save and select as format “CGATS SPECTRAL”.
10. Import the CGATS data in Color Pilot 16.x or newer.

PANTONE Library

All PANTONE ink books part of the Esko CMS database are M2 versions. If desired one can switch to the M1 versions as follows:

1. Open Color Pilot 16.x or newer.
2. Go to Edit > Preferences.
3. Click the General icon.
4. Click Ink Books.
5. Select M1 in the Measurement Condition for PANTONE Books drop-down list.

Proof Verification - the process of verifying with a spectrophotometer how good the proof sample is matching the press sample / profile

Proof verification requires the following objects:

• Press profile
• Proofer profile
• Proofing color strategy

Press profiles are either created (see previous paragraph Profile Run - the process of creating a press profile with Color Pilot 18.0) or imported. The ISO12647-2:2013 ICC profiles are not by default available in the Esko CMS database but you can download them from the color.org website to import in Color Pilot. Here is a direct download link:

• Coated paper > PSOcoated_v3.icc (based on the FOGRA51 characterization data): http://www.color.org/registry/PSOcoated_v3.xalter
• Uncoated paper > PSOuncoated_v3_FOGRA52.icc  (based on the FOGRA52 characterization data): http://www.color.org/registry/PSOuncoated_v3_FOGRA52.xalter

A proofer profile suitable to match M1 based press profiles like the PSOcoated_v3.icc one should be created with the M1 measurement condition (requires Color Pilot 16.x or newer ( * ) ) on proofing paper containing as much as possible the same amount of OBA's.

The level of OBA's is for each press substrate category (PS1 to PS8) described in the ISO12647-2:2013 standard. Five "fluorescence" levels are described:

• Coated paper (PS1) > PSOcoated_v3.icc: fluorescence level= Moderate (ISO 15397 8-14 ΔB)

• Uncoated paper (PS5) > PSOuncoated_v3_FOGRA52.icc: fluorescence level= High (ISO 15397 >14 ΔB)

Contact your press substrate supplier to know the level of fluorescence/ OBA for the used substrate. The same for the proofing paper, ask your supplier for a proofing paper with the same level of OBA's or consult the FOGRA website (use the OBA category filter): https://www.fogra.org/en/fogra-fogracert-en/prepress-en/proof-/proofing-substrate/certified-proofing-substrates/

Please note that there is no need for an M1 specific generic Esko EPL! You can use a default one:

• Page:
  KB185615059: FlexProofE, Pack Proof - How to install and use generic Esko EPL files

Inline verification with the Epson SpectroProofer

An M1 measurement with the SpectroProofer is only possible with the latest model, ILS30. The measurement condition can be selected on the level of the output device in the Esko Proof Client.

1. Open Esko Proof Client.
2. Select the Epson output device.
3. Go to the Special pane.
4. Select M1 - D50 UV included for Device mode.

Offline verification with the i1Pro2 or i1iO2

Choosing the M1 measurement condition can't be done in the Proof for Contract Approval ticket, hence you have to specify the measurement condition in the preferences of the verification tool. Note that you need the 2nd generation of i1Pro / i1iO in order to measure in M1!

1. Open Esko Verification tool.
2. Go to File > Preferences.
3. Click the General tab and select the correct spectro (X-Rite i1iO_i1iO2 or X-rite i1Pro2) in the Measure device drop-down list.
4. Choose M1 - D50 UV included in the Measurement conditions drop-down list.
5. Click the OK button and close the tool.

Visual assessment - the process of verifying visually how good the proof sample is matching the press sample / profile

Visual assessment should be done in a viewing booth compliant with the ISO3664:2009 standard. More information about this standard can be found in this document:
http://www.color.org/events/toronto/5-ISO_13655_Measuring_Conditions_RWC.pdf

Here you can find ISO3664:2009 certified systems: https://www.fogra.org/en/fogra-fogracert-en/print/cabinets-2-82/cabinets/iso3664systems/

Process control - the process of verifying how good the printing conditions in production are matching the printing standard target values

No workaround exists to measure single row control strips in M1 with i1Profiler. But you can follow this procedure in case an UgraFogra mediawedge is printed you:

1. At the Home page, select a CMYK printer and click Measure Reference Chart.
2. Select the correct Spectro at the Define Chart step.
3. Click the Load button and use this file ECI_MediaWedge_v30b.txt.
4. Select the Measurement step and measure the strip.
5. Click the Save button when finished with measuring the strip.
6. Choose i1Profiler CGATS Custom as the file type (see step 11 of the procedure to measure the P2P25 chart for the settings).
7. Open your PressSync curve set and load the txt file via Measure > Load Measured Data (CGATS).