Updating Smart Media color management

Overview

The Smart Media Definition (SMD) includes settings related to color management. For specific customers or jobs, sometimes you need to change settings to meet specific quality requirements. Over time, a new output ICC profile may be required.

In this situation, a color management expert needs to use the OVERRIDE COLOR dialog to create a new SMD with the required setting or profile changes.

General

The Override Color dialog can be accessed using the engineer "Spanner" icon in the Smart Calibrator's Start Calibration screen.

Document controls

The settings that can be changed include:

• Override color management in PDF
• Preserve 100% black
• Keep text black
• Color manage gray as CMYK

Override color management in the PDF

When enabled, the input ICC profiles override any found in the document. When not enabled, the Input ICC profiles are used only where they don't already exist in the document.

Preserve 100% black

When enabled, the black‐only part of your input is no longer converted to a CMYK‐equivalent color. This option is particularly relevant for black text because it avoids colored fringes.

Keep text black

When enabled, this setting keeps black text objects as process black.

When "Preserve 100% black" is enabled, this setting is enabled implicitly.

Color manage gray as CMYK

When enabled, monochrome (gray) data uses the selected CMYK input profile and is color managed as CMYK. When this option is selected, the Gray ICC profile setting becomes unavailable.

Output Rendering intents

The following rendering intents can be set:

• The main (default) rendering intent
• Override intents
  • CMYK images
  • RGB images

Intent hierarchy

You can set rendering intents in the document being printed, or in Smart DFE's color management settings.

If there are rendering intents set in the document, they take priority over the main rendering intent setting.

If the override intents are set, they take priority over all other intents.

Main rendering intent > Is overriden by > Rendering intent in document > Is overriden by > Override intents.

When "Color manage gray as CMYK" is checked, the CMYK images intent is also used as an override for gray images.

Absolute colorimetric

Any color that the device can reproduce (with the intended setup and viewing conditions) is reproduced exactly. Colors outside the device gamut are mapped onto a "nearby" point in the gamut. There are various ways in which a color might be out of gamut. For example, it could be too saturated, lighter than the paper color, or darker than the darkest imageable patch.

Colorimetric reproduction is appropriate where an exact color match is required. For example, you may choose a colorimetric strategy when you are reproducing a logo in corporate colors.

Relative colorimetric

This style aims to reproduce colors exactly, except that the luminance (how light or dark a color is) is scaled so that the darkest possible color is mapped to the darkest imageable color; the lightest possible color is mapped to the paper white. This style may change the hue (that is, the degree of redness, blueness, and so on) of any color, and is almost certain to affect the luminance of most colors.

Some scanners and applications produce data that has been adjusted so that the lightest and darkest points are encoded as maximum and minimum lightness. For interpreting this kind of image, the relative colorimetric style is appropriate.

Perceptual

This style maps the entire device‐independent color space onto the gamut of the printer; it compresses the range of in‐gamut colors to make room for out‐of‐gamut colors. It is appropriate for rendering photographs and similar reproductions of natural scenes.

Saturation

This style specifies that the saturation of the colors in the image is preserved, perhaps at the expense of accuracy in hue and lightness.

Input profiles

The Override Colors dialog gives an expert user the ability to replace input ICC profiles, including:

• RGB profile
• CMYK profile
• Gray profile

When an SMD is first created, a set of default input profiles is added.

If no profile is found in the SMD, the setting shows as "None"; SPC chooses an appropriate default.

Output profiles

The Override Colors dialog gives an expert user the ability to replace and add output ICC profiles, including:

• Printer profile
• Emulation profile

When an SMD is first created, a set of default input profiles is added.

If no output profile is found in the SMD, the setting shows as "None"; SPC chooses an appropriate default.

When Emulate another printer is enabled, the emulation profile is added to the color management chain (between the input profile and printer profile). 

Saving changes

If any required ICC profile is set to "None", the SMD cannot be created. Adding the required profiles enables the Create new media... button. 

ICC

This tab allows the user to create an ICC profile using default settings.

It also allows the user to view the gamut of the ICC that is being used.

Read Profile Charts

Browse to the Testchart created by ColorAnt

Template Configuration

This will change how the ICC is created. We have supplied 4 default options. 

All but 2 of the settings are the same for all 4 default templates we provide. The settings that differ are black start and pure gray.

• Option 1 - Has black start as 25 and pure gray on.
• Option 2 - Has black start as 25 and pure gray off. 
• Option 3 - Has black start as 35 and pure gray on.
• Option 4 - Has black start as 35 and pure gray off.

You can create your own templates and copy them to the installed location  then under Resources → IccConfigs.

If setup correctly you should be able to generate an ICC with custom settings (For the best results, don't change or remove the tokens). 

Import Data

This will launch Measuretool in order to measure the testchart you have just printed.

Update SMD

This will generate an ICC profile and update the SMD with it for use in SPC

Spot Colors

In the Spot Colors panel, you have the option to include spot colors, which can encompass technical separations, metallic inks, white backing, as well as traditional spot colors like Pantones.

To add a Spot Color click "+" and a Custom Color window is displayed.

This will show the mapped in gamut color and the Delta E color difference. You can manually change the Lab value or the CMYK Sliders to change the color. (Or CMYKOV sliders if you have a suitable ECG profile).

To remove a color, click "-"and a warning is displayed as below:

Other Actions

To import a TCB file (*.tcb) or CxF X-4 (*.cxf)  file with a list of spot colors, click "Import". If there are already spot colors in the list, a warning window is displayed as below.

Note : The location should match the default Centralized Ink location (found in SPC -> Engineer -> Folders -> Central Spot Library).

Note: Custom ink books can be exported from Esko in CxF/X-4 format. We will only facilitate a very limited set of operations with the CxF library, specifically limited to importing and exclusively involving CIELAB colors. 

Once imported, all the spots in the TCB/CXF X-4 file are listed as below.

If a color is out of gamut then a warning triangle is displayed. If you place your cursor over the triangle the delta E or color difference value is displayed to show you how far out of gamut it is.

If you select a color and right click, you have the option to “Rename Color”, “Change Color”, “Convert to Process Color” or “Replace with In Gamut Color”.

To export a .tcb file, click on "Export TCB". The "Export TCB" button on the "OVERRIDE COLOR - Spot Colors" defaults to the central location.We export to a subfolder based on the PrinterID, with the file named after the SMD located in the central library: [PrinterID][SMD_Name].tcb.

3D Gamut View: 

It allows the user to view the gamut of the ICC that is being used.

Click the checkbox of a color entry to show/hide the color in the 3D view; click the checkbox of "Spot Colors" to show/hide all spot colors in 3D view.

Update SMD

It allows the user to update the SMD to the server.

Export SMD

It allows the user to export the SMD locally.

Spot Variations Chart

This Tool provides a systematic approach for printing technicians to edit spot colors efficiently. By following these steps, you can achieve accurate color adjustments and enhance the quality of your printed materials.

This involves printing a reference patch of the original spot color along with adjacent patches that incorporate variations in cyan and magenta (or yellow) process color inks to achieve the desired ink mix.

The workflow consists of printing the original spot color and then introducing a small amount of cyan, magenta, or yellow to create the desired ink mix. The technician can compare this patch with the reference they are attempting to match. Once satisfied with the match, they proceed to adjust the spot color to reflect the CMYK values corresponding to the created patch.

The user has the flexibility to add or subtract up to three inks from an extended gamut ink set, excluding black.

Select on a desired Spot and click on the icon for Spot Grid Table

Choose any 3 colors from the list and a preview of the patches to be printed will be displayed, showing variations in color according to your selected parameters.

Increment: 

• Default 5% 
• Increment or decrement values -  0.1% (one decimal place) 

Click on Print and the PDF will be sent to the SPC's waiting queue.

Ignored Spots

1. Add a Spot Color to be Ignored:

   • Click the '+' button in the Ignored Spot Colors section.

2. Delete an Existing Spot Color:

   • Select the spot color you want to remove from the RIP.
   • Click the '-' button to delete the selected spot color.

This will affect how the new jobs are shown in the waiting queue, what spots are shown in the job editor and what spots are printed.