Product

Platform

Operating system

Error

Symptoms

Aliasing works but the spot color recipe in the PDF isn't updated. Therefore, the aliased color doesn't appear in Acrobat with its new color definition (e.g. if sc1 is aliased to sc2, then sc1 still appears in Acrobat with its sc1 recipe not the same color as sc2). This is also a problem with the RespectJobList workflow.

Cause

a) no other color-definition for sc2 (aliasing to a color not existing in the PDF)

b) more than one color-definition for sc2, using different alternate color functions

c) definitions for sc2 within a DeviceN color-space

d) definitions for sc1 within a DeviceN color-space

If you've said in the process plan that the document overrides the database and you've aliased scX to scY, when you look in Acrobat at the page after color mapping, scX will have a different color than scY even though they will be printed on plates and proofs with the same color.

If you had set the process plan to have the database override the document, they would have the same color (as defined by the database). Whenever possible (not for DeviceN) and requested (database values override PDF) the database values are also used to change color-alternates of spot colors that will not be mapped to process within the PDF. Because aliasing is done separately before mapping/matching, the alternate color would changed for the new color name (scY in your example).

There is no general solution for this and it is currently not implemented (see also PDF 1.3 maual about /Separation and /DeviceN color-spaces), for the following reasons:

a) If you map "Blue" to "Green" and there is no color-definition for "Green" within the PDF, you cannot change the alternate.

b) theoretical example (ColorSpace Resource in PDF):

/sc1 [/Separation /Blue /DeviceCMYK /"alternate function 1"]

/sc2 [/Separation /Green /DeviceCMYK /"alternate function 2"]

/sc3 [/Separation /Blue /DeviceCMYK /"alternate function 3"]

/sc4 [/DeviceN [/Red /Blue] /DeviceCMYK /"alternate function 4"]

/sc5 [/DeviceN [/Green /Pink] /DeviceCMYK /"alternate function 5"]

If you now map "Green" to "Blue", just change all appearances of /Green with /Blue (within /sc2 and /sc5). Where you take the new "Blue" alternate recipe from? From /sc1, /sc3 or the "Blue" part of /sc4? for /sc5 there even is no simple way to change the alternate from [/Green /Pink] to [/Blue/Pink]!

Note that the colorizations are still done with the resource names /sc2 or /sc5 and not done with the names "Blue" or "Green". So aliasing does not eliminate /sc2 it just changes its alternates color name.

Solution

If you want to change the alternate color of sc1 to the color from sc2:

1) Switch "Use ... Alternate from Color-Editor" on.

That is, the user should set the process plan setting so that the color database values override what's in the PDF document. "Use..." is just the text in the color-converter refine process plan to enable the color database override mode. "...sc2 must be present..." just says that the color for sc2 must be known in the color database and therefore has to be present in the JT spot color table (delivered by optimizer).

2) Ensure that the sc2 color is present in the spot color table.

In other words, the optimizer has to put the color definition into the jt param passed to the color matcher.

Permanent fix:

See also

Keywords

acrobat, refiner, spot color

Technical contact(s)

James Bredenhof

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Date submitted