First you have to decide whether you need a linearization of the primary colors.

A linearization is always helpful if the printing system tends to produce unexpected results, e.g., if the colors are much too dark due to a sharp tone value increase. A linearization helps to distribute color patches in the best possible way for this printing system. In addition, ColorAnt creates a very smooth and homogeneous linearization to avoid bumps in the distribution of color patches in a test chart.

However, a separate linearization step is not required if the printing system has been calibrated via the RIP, a dedicated CtP curve is used or if the printing system does not show any irregularities in the output.

Profiling without Linearization

Open the Custom Chart tool, select Create Profile from the Intended Use drop-down menu and then the Color Space.

Select the Number of Patches and continue as described above.

Profiling with Linearization

Linearization requires additional linearization measurement data from a linearization test chart. This linearization test chart must be printed on your printing system and measured with a spectrophotometer. Load the measurement data into ColorAnt before opening the Custom Chart tool.

Note: Linearization charts can be created with the Custom Chart tool by using the Linearization option from the first drop-down menu. However, a predefined chart can also be used. For example the file Linearization-CMYK-v1.txt for a CMYK system (see screenshot), which is provided by ColorAnt under File/Open Predefined, or the file Linearization-5CLR-v1.txt for a 5-color CMYK+X printing system.

Select the desired measurement file in the drop-down menu Reference file. ColorAnt automatically recognizes the color space and the channel names.

Select the Number of Patches and continue as described above.

Note: Requires a ColorAnt L license.

As for the standard color spaces Gray, RGB and CMYK, you first have to decide whether you need a linearization of the primary colors.

A linearization is always helpful if the printing system tends to produce unexpected results, e.g., if the colors are much too dark due to a sharp tone value increase. A linearization helps to distribute color patches in the best possible way for this printing system. In addition, ColorAnt creates a very smooth and homogeneous linearization to avoid bumps in the distribution of color patches in a test chart.

However, a separate linearization step is not required if the printing system has been calibrated via the RIP, a dedicated CtP curve is used or if the printing system does not show any irregularities in the output.

Profiling without Linearization

Open the Custom Chart tool, select Create Profile from the drop-down menu and then the Color Space.

Select the Number of patches and continue as described above.

Profiling with Linearization

Linearization requires additional linearization measurement data from a linearization test chart. This linearization test chart must be printed on your printing system and measured with a spectrophotometer. Load the measurement data into ColorAnt before opening the Custom Chart tool.

Note: Linearization charts can be created with the Custom Chart tool by using the Linearization option from the first drop-down menu. However, a predefined chart can also be used. For example the file Linearization-5CLR-v1.txt for a 5-color CMYK+X printing system, which is provided by ColorAnt under File/Open Predefined.

Select the desired measurement file in the drop-down menu Reference file. ColorAnt automatically recognizes the color space and the channel names.

Select the Number of patches and continue as described above.

Defining Multicolor channels

For generic Multicolor test charts, define the number of channels and their names (with or without CMYK) as close as possible to the colors used on your printer. It is not necessary to define the channel colors exactly in the reference data. Just make sure that you come close to the type of color so that the correct color combinations are generated. For example, if you want to print violet, you can select blue as the channel color, but not green, red or cyan.

Note: When creating Multicolor profiles with CoPrA, three chromatic colors + optional black + a maximum of three gamut expanding colors are supported. Some examples of possible combinations are: CMYK+Orange, CMY+Green+Blue, CM+Orange+K, CMYK+Red+Green+Violet, etc.
Other non gamut extending colors positioned within the CMYK color gamut may cause problems in profile creation. Use the Spider Web in the View dialog to check the measurement data for problematic color combinations.

For prints on black substrates, such as textiles, white ink must be used first and colors must be applied on top of the white ink to obtain colorful graphics. Special test charts are required to create profiles containing White.

Color Space: CMY+W and CMYK+W: For color managed color prints on colored (mainly black) substrates,white ink must be used. If white inks are to be used for the separation, special test charts are required which can be created using the CMY+W and CMYK+W color space options.

Note: These charts are displayed with a black background in the Export Chart tool to simulate the black substrate. Keep in mind that the patch information and gaps between patches when exporting the chart will be printed with the white ink, hence even if they are existing they do not show up when opening such charts in image editing tools or PDF viewers.

Creating charts for spot color libraries is straightforward:

1. Open the Custom Chart tool and select the option Spot color library from the Intended Use drop-down menu.
2. Specify the desired Number of spot colors for the library, and decide on the Number of patches per spot color.
   
   
3. This creates a custom chart for spot colors under Data Sets with the color model Spot (indicated in the DCS column).
   
   
4. Depending on the entered Number of patches per spot color, corresponding gradients are generated for each color.
   
5. Define the spot colors and the spot color names. Spot colors can be defined by clicking the pipette icon and selecting a color from the list. They can also be imported by opening a data file containing the desired sport color.
   
   By clicking on the pencil icon, a spot color can be defined by entering its Name and Color value.
   
   The color can also be selected by clicking on the color field to open the color selector.
   
6. The created chart can then be exported using the Export Chart tool (see below) and subsequently measured to generate the custom spot color library.
   Note: If the library has been created and you want to rename one or more spot colors later, this can be done in the Text tab of the View dialog.

Note: In this way, charts for custom spot color libraries of up to 99 spot colors can be created. If larger spot color libraries are required, several small libraries can be created and then combined using ColorAnt’s Link tool with the Merge by channel name checkbox enabled.

General Information

CoPrA supports three main chromatic primary colors which should span a suitably large gamut encompassing the gray balance. Typically, this is CMY but it can be any other appropriate chromatic color combination.

Black can be added optionally as a 4th channel. If black is used it must be the fourth channel.

Up to two gamut extending colors can be used in between each section of the main primary colors.

Note: Following this approach, printer profiles of up to 10 channels can theoretically be created by CoPrA 5 and higher. However, it is not recommendable to use printer profiles with more than 8 channels in production as every additional channel increases the profile size exponentially so that either a very low grid size or an exorbitantly large profile had to be used.

Examples

Typical Multicolor Application
When using a typical Multicolor color space with CMYK parts, the additional inks Green, Orange and Violet extend the gamut in each section of the three primary colors. In between each section, a single gamut extending color is used creating a color space with 7 colors.

Advanced Multicolor Application
Some inkjet printers use Red and Orange in addition to the standard CMYK inks. CoPrA is able to profile such a 6 color printer since Orange and Red are two gamut extending colors of the main primary color sections Yellow and Magenta.

Note: When working with two gamut extending colors, special test charts must be used. CoPrA provides appropriate Multicolor test charts which are available via Tools > Open Testcharts folder > Multicolor.

Special Inks
In industrial printing, such as ceramic printing, the main colors are often supplemented by additional light (e.g. Pink) or dark (e.g. Brown) inks. Another example is Flexo printing, where a Gray ink supplements the Black ink to better render lighter grays in the artwork. These colors are what we call special inks, and they can be used with the special Multicolor Modes in CoPrA.

Supported Color Systems

CoPrA allows to create printer and DeviceLink profiles for all types of color spaces Gray, RGB, CMYK and Multicolor. Cross color space profiles are also supported, such as RGB to CMYK, CMYK to Grayscale or RGB/CMYK to Multicolor.

The following color systems are supported:

• 2- and 3-color systems
• 4-color systems with CMYK
• 4-color systems with CMY + either Red or Green or Blue, without Black
• 5-color systems: CMYK + either Red or Green or Blue
• 5-colour systems: CMY + either Red+Green, Red+Blue or Green+Blue, without black
• 6-colour systems: CMYK + either Red+Green, Red+Blue or Green+Blue
• 6-colour systems: CMY + Red+Green+Blue, without Black
• 7-colour systems: CMYK + Red+Green+Blue
• 8-color systems: CMYK + Red+Orange+Green+Blue
• 9-color systems: CMYK + Red+Orange+Green+Blue+Violet
• Special ink combinations such as CMYK+Gray, CMYK+Pink+Brown, etc.
• The CMY channels can even be exchanged for other similar colors, e.g. Magenta for another reddish color or Yellow for Beige and so on.
• Creation of DeviceLinks with up to 9 channels

To create Multicolor profiles various test charts (multichannel Photoshop PSD files) with associated reference files are available for measuring with ColorAnt (or any suitable measuring software). These Multicolor test charts can be found in the folder Testcharts (in CoPrA's installation folder). The folder can be opened directly in CoPrA (menu Tools > Open test chart folder). The contained Multicolor test charts are specifically optimized for the algorithms used by CoPrA. Alternatively, you can create your own test charts for your multicolor process using ColorAnt/Custom Chart.

Selection of the correct test charts for your printing process is facilitated by the naming. Therefore, please note the following naming conventions:

• The name of the test chart contains the number of channels, the color combination and the number of color patches.  The test chart name CL-CMYKB-2140 reflects that it is a 5-channel test chart with the color combination CMYK+Blue and 2140 color patches.
• However, by 'Blue' we mean a fairly broad color range of reddish to greenish blue. For example, it contains violet as well.
• The following color abbreviations are used in folder and file names: R = Red, G = Green, B= Blue, V= Violet, O = Orange, Yg= Yellow-Green.
• For a Hexachrome printing process with CMYK+Orange+Green, use the corresponding test chart, CL-CMYKRG. Here, CMYKRG stands for CMYK+Red+Green, whereby red includes orange.
• For 7-color printing use the test chart CL-CMYKRGB. In addition to the colors CMYK it also contains the additional colors Red+Green+Blue.
• Nine special test charts for 6C and 7C color combinations have been available for two Gamut-extending colors (e.g. CMYK+Red+Orange). They can be found in the folder Special.
• The layout of the supplied test charts is designed to fit on A4 or US letter size and is optimized for the hand-held measuring devices supported by the Measure Tool. As all patches cannot go on one page the Multicolor charts are split in multiple pages which need to be measured in corresponding sequence (1_6 means it is the first of six pages).

Important Notes

• The total area coverage (TAC) of 400% is not exceeded in any of the test charts, not even in Multicolor test charts.
• Please make sure that the RIP or the output system of the printer supports Photoshop multichannel PSD files. If this is not the case please open the test charts in Photoshop (or another suitable image editing program) and save them as DCS2 files.
• The test charts are optimized for the X-Rite i1Pro measuring device, but can also be measured with other any single color measuring devices.
• For measurements with the X-Rite i1iO, Barbieri Spectro LFP and Konica-Minolta FD-9, we recommend creating a customized test chart file based on the corresponding reference file using ColorAnt’s Export Chart tool.
• To use a measuring device that is not supported by ColorAnt MeasureTool, it is necessary to create a test chart which is suitable for that measuring device and the intended printing process. Make sure to select the reference file matching the color system. We recommend creating the corresponding reference files with ColorAnt/Custom Chart. Please note that our reference files use a maximum total area coverage of up to 400%, even for 7 channel color systems.
• For Multicolor profiling - in contrast to CMYK Profiling - the test charts has to be adapted to the calculation algorithms in order to minimize color patches, otherwise, test charts would be exceptionally large.
  Note: Multicolor profiling differs from manufacturer to manufacturer. If you would like to use measured Multicolor test charts from other manufacturers in CoPrA, please note that these test charts may not achieve optimal results in CoPrA.
• If it is not possible to reprint CoPrA's test charts and use existing measurement data from Multicolor test charts of other manufacturers, it is recommended to optimize these measurement data using ColorAnt before creating profiles in CoPrA. The Rescale tool allows adaption the measurement and reference values in ColorAnt according to suitable CoPrA test charts. Any missing measurement values will be interpolated which may result in inaccuracies if alternative test charts of other manufacturers reveal many gaps.
• Special test charts, such as CMY test charts for printing systems that do not use black, are also available in the Testcharts/Multicolor folder.

For example, when working with CMY+Blue, use the appropriate test chart from the folder CMY+B.

Note: Previously, many users worked with standard CMYK test charts, such as ECI2002 or IT8/7-4, for color combinations without black, replacing the K channel with blue, e.g. CMY+Blue. Although this approach seems practicable at first glance, it is not recommended, because the process color black plays an entirely different role to a gamut extending color blue in CMYK test charts. Accordingly, many color combinations in the CMYK test charts are unnecessary, or even missing for a blue process color. It is preferable to use CoPrA in combination with CMY+X test charts in order to obtain the best possible profile quality.