Dynamic Profiling

The following advanced settings are available for dynamic separation profiles:

• TAC (Total Area Coverage):This lets you adjust the maximum amount of ink in percent.
• Black Start: This option specifies the percentage at which Black ink is starting to be used and is defined by the separation rule. You can define a higher black start here, which will affect only CMYK inks, not any additional inks that might be part of the ink configuration.
• Black Point Compensation: This can be increased to minimize clipping in shadow areas, preserving image details and allowing full use of the output color space's dynamic range in the shadows. In most cases, increasing the black point compensation will also lead to a general decrease in saturation. If the black point of the target color space is darker than the black point of the source, black point compensation might increase the saturation. If you need a color as deep black as possible or want to avoid color shifts, you can decrease or deactivate black point compensation by moving the slider to the left.

  We recommend to use a high value for CMYK-to-CMYK separations of image data and to use a low value for packaging printed on coated media.

• GCR Level: The amount of Black is defined by the separation rule. By increasing the level of GCR (Grey Component Replacement), you can reduce the amount of CMY in grey areas while increasing the amount of Black. Thus, less ink can be used and the resulting output is less sensitive to changes in the printing variables. If the GCR level is set to 0, the total Black ink will be the sum of the Black ink usage for single colors as defined in the separation rule. This setting affects only CMYK inks, not any additional inks that might be part of the ink configuration.
• Grey Adjustment to Target Media: This defines how much the paper tint of the target print medium will affect the printed colors. This setting is important if the target printing condition uses a substrate with a different white point than the document's output intent and mainly affects the grey balance and less saturated colors.

  The default is 30, which in most cases is the ideal value to ensure a harmonic visual appearance. Setting the value to 0 will preserve the original colors as best as possible and thus ignore the new paper tint, increasing the value will have more impact on colors, especially on highlights and grey balance.

• Gamut Expansion: This allows you to exploit the full available color space of your printer and is useful for all printers with a large color space, with CMYK only or with additional inks. Using gamut expansion will boost colors to the edge of the available printer color space and might change them drastically, while the grey balance remains unchanged.

  Please note that color boosting is only possible if the target color space is significantly larger than the source. If your printer uses additional inks, also select the option Allow Additional Inks in Overprints from the purify settings for a maximum effect.

• Allow Additional Inks in Overprints: This defines how strictly the ink splitting definition from the separation rule will be applied to overprinting colors. If enabled, the overprint settings from the separation rule will still be regarded, but GMG OpenColor might also use additional inks if it makes sense to do so. Allowing additional inks in overprints is especially useful in cases where the resulting color will be substantially different from the individual colors, for example, when blue is overprinted with yellow.