Mar 182011
 

The story doesn’t end with a colour profile, some profiles have a larger colour gamut than other profiles, so what happens to colour that can not be produced? This is where something called a “Rendering Intent” comes into action. It the way that colour is mapped between profiles. You may note that in my example above that i have selected “Relative Colorimetric” intent under conversion options. There are 4 primary rendering intents as follows:

Relative Colorimetric

  • Will keep all producible colour as accurate as possible and forget any “out-of-gamut” colour (colour that can not be produced). This is the most commonly used intent for accurate reproduction of spot colours and also contract proofing in the offset printing industry. This is the best across-the-board setting to use for the print industry.

Absolute Colorimetric

  • The same as Relative colorimetric although will map in a white point simulation. This is almost exclusively used in contract proofing for the offset industry where the proofing paper used on a digital proofer (carefully calibrated and profiled inkjet printer set up to exactly match the offset press) is usually much whiter than the offset stock used. This will print a light colour in the background of the file to closer represent the offset result.

Perceptual

  • This rendering intent will maintain the majority of the colour that can be accurately produced but will move “out-of-gamut” colour into the edge of what can be produced. This means that the outside of the reproducible colour will change but you will maintain some shadow detail that would otherwise be lost. This setting is best used when working with photographs.

Saturation

  • This intent follows the theory that as long as everything is bright and clearly the chosen colour, the rest will be likely to shift. This is best ONLY used in things like office presentations where spot colours and photos do not need to be produced accurately. This intent is used by windows (printer drivers etc).

If you convert a file from RGB to CMYK and use different intents the colour information inside the file WILL be changed and the output result will vary, this is why when consulting at a location with more than 1 computer that files travel through, that the manager make some well thought out selections for these setting and implement them as company file workflow policy. Even take a screen grab as I have done above and keep it in a manual for future reference. This will standardise what is being done and eliminate wasted labour and consumables trying to duplicate an earlier result with random settings.

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