The Tab Black Generation: Black Generation and Black Control Range

Black Generation

Various modes for black generation are available for both the creation of printer profiles as well as the creation of DeviceLink profiles (printer profiling: New Printer Profile > Customize > Rider Black Generation, DeviceLink profiling: Device Link > Customize > Rider Black Generation).

The setting for Multicolor Mode in the control panel Black Generation defines how colors are composed within their individual separations. Further information can be found here. The setting Mode defines the method for the generation of black in the target color space and therefore influences the separation comprehensively.

The following methods are available in the drop-down menu Mode:

  • Auto: Selects a medium GCR amount which is based on the measurement data.
  • UCR: Allows adjustment of the settings Black Start and Black Width.
  • GCR: Additionally allows the adjustment of the setting GCR Amount.
  • MinK: Only uses a minimal amount of black and generates a separation using the maximum amount of CMY.
  • MaxK: Uses a maximal amount of black and generates a separation using the minimum amount of CMY.

The methods UCR, GCR, MinK and MaxK generate a new separation, regardless of the separation of the target profile.

Additional methods are available for the creation of DeviceLink profiles:

  • Target Profile: Uses the separation of the target profile.
  • Preserve Black: Linearizes the black value of the source profile and prevents changes.
  • Preserve Separation: Preserves the ratio between the black channel and the black composed of CMY.
  • Save Ink: Replaces CMY colors by black to save CMY inks.

The options Preserve 0% Black and Enhance Shadows are only available in DeviceLink profiling.

  • Preserve 0% Black is available when the mode Preserve Separation has been selected. It prevents the generation of a black channel in source colors without black. This is important for some overprint applications.
  • Enhance Shadows is also only available when the mode Preserve Separation has been selected. This intelligent black option prevents drawing losses and weak shadows.

Notes

The black generation mode Preserve Separation is especially important for the conversion between two CMYK color spaces, because it ensures that the ratio between CMY and black which is used to generate gray is maintained in the color conversion.
When the mode Preserve Separation is selected, the option Enhance Shadows should always be enabled.

GCR Settings

The GCR settings include GCR Amount, Black Start and Black Width.

  • GCR Amount: Defines the amount of CMY that is replaced by black. At 0 only a low GCR amount is used which mainly impacts the shadows whereas at 100 a very strong GCR is used which effects the shadows and the highlights.
  • Black Start: Defines the starting point for the black generation. Black will be used if the minimum amount of C, M, Y exceeds this limit.
  • Black Width: Defines the range in which black is generated outside the color-neutral area. The lower the value the less black will be generated outside the color-neutral area.

The options 100% Black and Pure Gray are only available in printer profiling.

  • 100% Black prevents, among other things, that a pure black RGB text is printed in four colors after conversion into a CMYK profile which would result in a blurred looking text. This is often the case with Office documents. The enabled option 100% Black converts an RGB value of 0-0-0 to CMYK 0-0-0-100 (i.e. 100% black).
  • Enabling the option Pure Gray in a CMYK printer profile results in a gray balance which is composed of black ink only. However, this only makes sense if the printing system features a very neutral black from shadows to highlights.
    Enabling Pure Gray in an RGB printer profile results in a gray balance which is composed of equal amounts of RGB values. This option proves to be useful in RGB-controlled ink systems.

Black Control Range

The Black Control Range controls the transition to black. If black exceeds the limit, CMY colorants will not be modified and black is linearly added. Up to the specified value black will be calculated accurately. A value of 0% indicates that only CMY will be converted whereas black will be linearized. If a proof requires an exact colorimetric reproduction the slider should be set to 100%. 80% is a good value to achieve a smooth transition in the shadows.

 

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