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Tell me about the color management model for remote proofing

This section describes the model used for color management in the Remote Proofing software. It assumes some understanding of color management. In general, to implement a proofing workflow, two color transformations have to be performed:

  • Input transformation: first the input data, possibly in different color spaces, has to be transformed to the color space of the final output device: that is, the device, such an offset press or a digital press, with which the final material will be produced.
  • See Input color transformations.

  • Proofing transformation: then the graphical content has to be transformed from the final output device's color space to the color space of the Designjet 10ps, 20ps, or 50ps to ensure an accurate emulation of the final result on the Designjet printer.
  • See Proofing color transformations.

See also:

 

Input color transformations

In general, the input graphical content can be described either in a device-dependent color space (DeviceCMYK, DeviceRGB or DeviceGray in PDF terminology) or a device-independent color space (such as CIELab, CalRGB, or CalGray).

For device-dependent color spaces the following transformations are performed:

  • DeviceCMYK or DeviceGray: these are supposed to be in the final output device’s color space, so no transformation is performed.
  • DeviceRGB: the graphical content is transformed using your chosen RGB input profile and the final output device’s color profile.

Device-independent color spaces are transformed to the final output device's color space using the final output device’s color profile.

In any case, when a transformation is performed, a rendering intent has to be used. You can select the rendering intent to be used for all the input transformations. This rendering intent is used if there is no rendering intent specified in the input file. Rendering intent can be specified in an object proof file (see page 14).

 

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Proofing color transformations

Once the graphic contents are in the final output device’s color space, they have to be transformed to the Designjet’s color space. This is done using the final output device’s color profile and the Designjet’s color profile. The latter is automatically selected depending on the media type and print quality settings.

In this transformation, a rendering intent has to be used. For proofing, the only color intents that make sense are 'Absolute Colorimetric' (emulate the final printing substrate white) or 'Relative Colorimetric' (do not emulate the final printing substrate white).

 

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Spot colors

There are two possible uses of spot colors:

  • A spot color may be used by the designer to refer to a specific standard color (such as a PANTONE color) that will be printed on the final output device using process inks (CMYK). In this case, the spot color may not be accurately reproducible in the process ink color space.
  • In other cases, spot colors represent inks (tints) that will be used in the final printing process.

The Remote Proofing color management model supports both uses of spot colors, but they are mutually exclusive. That is, either all the spot colors are treated as different tints or all of them are treated as if printed with process inks.

 

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Color management choices

In summary, the choices you can make to control color management in the Remote Proofing workflow are:

  • Final output device ICC profile: this is the CMYK profile that describes the final output device (offset press, digital press, etc.). Also known as the 'emulation' or 'reference' profile because it is the profile of the device that has to be emulated by the proofer.
  • RGB input profile: input profile to be used to transform RGB input.
  • Input rendering intent: rendering intent for input transformations. Any rendering intent is valid.
  • Proofing rendering intent: rendering intent for the proofing transformation (only two rendering intents are possible).
  • Handling of spot colors: they can be treated as if printed with process inks or with separate tints.

 

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