Rich Black over Rich Black

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    • #74168

      HELP – I have a graphic frame-with background of rich black, importing a vector eps with no background, over identical graphic frame of rich black (page colour).
      When printed as cmyk offset, the first graphic frame printed in a flatter black. Why?
      I have checked all the colour breakdowns on the pdf and original inDesign file and they all register identically at C20 M20 Y20 K100. The Print Preview showing ‘all blacks accurately’ shows frames as identical.
      Is something magical happening in prepress? Why would these frames print differently? Am I seeing things? or not?

    • #74175
      Colin Flashman
      Participant

      “Is something magical happening in prepress?”

      Possibly, but that is something you should ask your offset printer first. Any chance you can do some screen-captures to show what is happening? They can’t be attached directly to this post, but hyperlinked to an image hosting site like imgur; or file sharing site like dropbox.

    • #74177

      It’s hard to say without seeing your PDF, but some suggestions:

      1. Make sure there are no spot colors in your EPS and InDesign file (If you have raster effects such as transparency and drop shadows, spot colors will ruin everything)
      2. Make sure your EPS files are CMYK (File->Document Color Mode)
      3. Export to PDF x/1a
      4. Check separations in PDF

      Rich black is not universal, I assume your printer gave you those builds? If not, they may have changed them on one and not the other.

    • #74181

      Thanks for your responses. I suspect Colleen may be right: – “Rich black is not universal, I assume your printer gave you those builds? If not, they may have changed them on one and not the other.”

      Yes Printer gave me the rich black formula.
      See pdf cover only at https://www.dropbox.com/s/ajappdyjonlf0ni/Test1.pdf?dl=0
      See how it printed: https://www.dropbox.com/s/yviin2r259na6zf/AeromilCoverIssue.jpg?dl=0

      1. Make sure there are no spot colors in your EPS and InDesign file -CHECK
      2. Make sure your EPS files are CMYK (File->Document Color Mode) -CHECK
      3. Export to PDF x/1a -CHECK
      4. Check separations in PDF -CHECK

      The only thing that I can see that is odd is that there is a background on the frame with logo when there does not need to be. However, it should not affect the printed output, right?

      Printer claims the issue was not visible until the ink dried….

    • #74182
      David Blatner
      Keymaster

      Remember that InDesign has its own Separations Preview feature which might be able to help clear this up. Claudia McCue wrote about the Separations Preview panel in detail in Issue 67 of InDesign Magazine.

    • #74183
      Colin Flashman
      Participant

      Just tested the PDF and the separations looked fine on my screen. The frame you are speaking of is likely to be the frame that contained the eps logo in InDesign. Has your printer offered an explanation as to how this may have happened, and if so, what was the explanation? Does the printer have a procedure in place for handling non-conformance issues like this?

      Was this the only page that this happened on or was this throughout the document?

      I have occasionally seen results like this but NOT on an offset print, but digital colour copies… where the black was 100K only and the graphic above had an unexpected effect on it that wasn’t visible. In instances like this, the Fiery RIP would make the 100K areas print so dense it was closer to registration colour than black; but anything that was where the graphic frame was would just be matt and dull. Ultimately I don’t think this is what is happening in this instance.

    • #74188

      “The frame you are speaking of is likely to be the frame that contained the eps logo in InDesign.” YES, it has nothing to do with the eps, it is used multiple times without this same effect.

      “Has your printer offered an explanation as to how this may have happened, and if so, what was the explanation?” Printer: The file is bad, too many layers and colour modes. On investigation this is not the case.

      “Does the printer have a procedure in place for handling non-conformance issues like this?” Apparently not. I am trying to resolve what the technical issue is. This will ascertain responsibility.

      “Was this the only page that this happened on or was this throughout the document?” This happened throughout. 2 instances with the logo where the frame was assigned a background colour. Other areas where a frame has been added over a photo to fade to black background. This frame extended further than the photo in places. In the inDesign file, the same formula black was used on these overlays.

      At this point, I am pretty sure that the rich black was altered at some stage, not taking in account these unusual instances and the result was these patches. I think inDesign is innocent. The original iD file is not perfectly constructed – in my opinion – with multiple people working on it, but colour-wise it seems correct.

      There seems to be no technical reason or instance where rich black over an identical rich black should render this way.

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