In this article, you will learn
- what the priority of the separation order is and what role it plays,
- how the CMYK and KCMY settings affect the separation,
- what recommendations we can provide for using this parameter in a profiling project.
1. Introduction
When calculating a characterization profile, the color values used to reproduce each color tone in the input data in the target printing system are determined. For saturated chromatic colors, this mapping is generally unambiguous. Neutral or near-neutral colors, however, can be reproduced using different color combinations. For example, the same gray tone can be reproduced either primarily through the combined use of Cyan, Magenta, and Yellow or primarily through Black. Under defined printing and viewing conditions, both variants produce the same visual color impression but differ in terms of ink consumption and process stability.
To ensure an unambiguous separation for such colors, it must be defined which color values should be given preference when a color can be reproduced using either a CMY-based or a Black-based separation.
Figure 1: Gray build-up with different separation order priority (schematic)
2. Functioning
When separating a neutral or near-neutral color, there is often a degree of flexibility between a CMY-based and a Black-based reproduction. The priority of the separation order determines which of these two options is preferred within this flexibility during the calculation.
With the CMYK setting, the separation prioritizes building gray tones using Cyan, Magenta, and Yellow. In certain cases, this can result in a gray tone being separated completely without any Black component.
With the KCMY setting, gray tones are preferentially built using Black. Black therefore takes priority over the CMY components, so that neutral colors already contain a higher proportion of Black in lighter tone values.
2.1. CMYK Priority
With the CMYK setting, the available flexibility is used in favor of Cyan, Magenta, and Yellow. The Black Channel is only used to the extent defined by GCR and Black Start. This can result in a gray tone being separated entirely without a Black component, even though a Black-based reproduction would also be possible.
2.2. KCMY Priority
With the KCMY setting, the available flexibility is used in favor of Black. As a result, neutral colors already contain a higher proportion of Black at lighter tone values, while the proportions of Cyan, Magenta, and Yellow are reduced accordingly. The fundamental onset threshold and the extent of Black generation are still determined by Black Start and GCR.
Figure 2: Black proportion in gray build-up depending on tone value and priority (schematic)
2.3. Relationship with GCR and Black Start
The priority of the separation order is closely related to other parameters of Black generation.
- GCR – determines the extent to which the common achromatic component of a color is replaced by Black.
- Black Start – determines the tone value at which Black is first introduced.
A neutral gray tone that could also be reproduced entirely using Cyan, Magenta, and Yellow in colorimetric terms is, with the CMYK priority, generated predominantly or exclusively using these CMY components. With the KCMY priority, a Black component is already used for the same color, even though the color could also be reproduced without Black.
Low Impact at a High GCR Level
Please note that the influence of the separation order priority depends on the selected GCR level. At a high GCR level, the achromatic component is already largely replaced by Black, leaving little available flexibility for either priority to have a significant effect.
3. Use in a Profiling Project
You can find the Priority of the Separation Order parameter [1] in a profiling project under the Separation Parameter tab of the Create Characterization Profile step.
Figure 3: The options available under the Separation Parameter tab of the Create Characterization Profile step
The parameter determines which color values are preferred when calculating neutral colors, within the available flexibility defined by GCR and Black Start. The setting is made using two radio buttons.
The following recommendations apply to the use of this parameter:
- CMYK (default selection) – this setting is suitable in most cases and avoids an unnecessarily high proportion of Black.
- KCMY – use this setting if a particularly stable, Black-based gray balance is desired. Please note, however, that this can also increase graininess in some areas.
Article Update: $PRODUCT_NAME_WORKFLOW 2.3.0 – 09/2026