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  • 1.  Changing white point and my P2P fails

    Posted 06-07-2024 08:56 AM
    How do I change the white point on an Epson proof so that it simulates the paper stock better without having my P2P chart fail? 
    I've created a new profile/baseline and when I change the paper white my P2P fails. 

    Thanks,
    Keith

    Keith Kusmierczyk
    Fry Communications Inc.
    101 Fry Drive | Mechanicsburg PA 17050-2654
    Phone: 1-800-334-1429 ext.4112
    keith.kusmierczyk@...

         


  • 2.  RE: Changing white point and my P2P fails

    Posted 06-09-2024 06:37 PM

    You haven't quite explained what sort if failure this is. Proof compliance is demonstrated by reproduction of a profiling chart, not a P2P, and the target is the press color space overall, without specific reference to gray balance and NPDC, rather dE avg/max/95th percentile, CMY and K solids, etc. So it is possible for a proof to pass as a proof but fail in NPDC, for example. I've seen this happen. Seeing the data I'm sure many members will recognize the specific problem you're having.

    Mike



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    Mike Strickler
    MSP Graphic Services
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  • 3.  RE: Changing white point and my P2P fails

    Posted 06-10-2024 10:31 AM
      |   view attached

    Hi Keith,

    Are you using the SCCA Calculator to change your profile chart data?

    I use this for simulating stock colors that are different than our Gracol2013Ctd Epson stock and it works really well.

    The instructions are included on the first sheet of the Excel document. Let me know if you need help with the Epson Workflow or Media Configuration.



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    James Harmon G7 Expert
    Pre-Press Technician
    SG360
    Wheeling IL
    (630) 400-4236
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  • 4.  RE: Changing white point and my P2P fails

    Posted 06-10-2024 10:55 AM

    It's not clear what the OP is talking about, but even if the target P2P reference is adjusted for the new white point this does not guaranty that the proof will automatically fall into compliance on all metrics. 



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    Mike Strickler
    MSP Graphic Services
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    Original Message


  • 5.  RE: Changing white point and my P2P fails

    Posted 06-11-2024 10:11 AM

    Assuming that you're using absolute colorimetric as your rendering intent, If you use X-Rite i1Profiler you can generate a new (source) profile with a new white point. Just measure the press paper you want to simulate and enter that as your white point.

    Like Mike, I'm not quite understanding why your P2P would fail since in the G7 world, white point is relative.....G7 neutral and NPDC are not based on a specific white point since the metrics are adjusted relative to whatever white point you have.
    If you're targeting (for example) GRACoL2013 specifically, then white point matters of course. If what you want is a "GRACoL" proof but adjusted for your press papers, then simply download the GRACoL/CRPC-6 characterization data and adjust the white point either through the SCCA calculator or using i1Profiler's white point adjustment feature.



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    Terence Wyse G7 Expert
    OPS R&D Senior Color Specialist
    Shutterfly
    Fort Mill SC
    (704) 207-4054
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