4 Replies Latest reply on Jan 17, 2014 7:41 AM by G.Hoffmann

    Why can one spot colour convert into two different sets of CMYK values?

    Sitting Giant Level 1

      Working within Illustrator CC, I have an EPS file of a logo which has a colour fill value of:

      Pantone 152 U

      CMYK: 0C 51M 100Y 1K

       

      When I copy and paste this into a new document I get a much duller colour (orange) with colour values of:

      Pantone 152 U

      CMYK: 2C 57M 83Y 2K

       

      I have enabled 'ask when opening' & 'ask when pasting' for Profile Mismatches in Edit->Color Settings->'Color Management Policies' - no warning shows up.

       

      I have also tried turning off, changing color management policies.

       

      I've opened the original eps file and assigned my working space profile (Coated FOGRA39) and then try copy and pasting without success.

       

      Help!

       

      sample.gif

        • 1. Re: Why can one spot colour convert into two different sets of CMYK values?
          jdanek Level 4

          My guess is the original equivalents were created by an older version of Illustrator.  Don't forget, the file that uses Pantone 152 will print using that spot color on press.  But, there are numerous complaints by users who are encountering the same problem you are.  It has to do with Illustrator's Pantone Plus libraries, a new LAB defintion and adjusted CMYK percentages in newer versions of Illustrator.  If you have a chance, prep 2 copies of the original file ( 1 with the older CMYK equivalents, 1 with the newer CMYK equivalents ).  If you have a decent proofer, print both and see which one resembles the swatch 152 ( from a swatch book ).  Preview images that dullen within CC may or may not be closer to the actual spot color swatch.  I just did my own comparison using your capture above and the first sample is closer to my swatch book.  I would creste a color swatch in Illustrator manually and apply the older percentages in the color sliders and use that instead of the conversion in CC.

          • 2. Re: Why can one spot colour convert into two different sets of CMYK values?
            G.Hoffmann Level 3

            In addition to John's useful comments:

             

            Using Pantone 512U (uncoated) isn't correct for Coated Fogra.

             

            Why can one spot color convert into two different CMYK sets if converted by the user?

             

            Assumed, the one spot color is uniquely defined by one Lab set:

            – the CMYK spaces are different

            – the CMYK spaces are the same but the Rendering Intents are different

            – the CMYK spaces are the same but the Black Point Compensations are different

               (on or off for Relative Colorimetric).

             

            Assumed, the spot colors are equal by name, but valid for different versions, both in Lab:

            – this obviousl at present the most common source of deviations.

             

            Assumed, the spot colors are defined by CMYK:

            – a chaotic situation which I wouldn't even like to dicuss.

            – CMYK to CMYK conversions should be avoided under all circumstances.

             

            The solutions:

             

            If the spot color will be printed always and everywhere by Pantone spot ink:

            – purchase an actual Pantone color fan und discuss with the printer the mixture for the selected ink.

             

            If the Pantone color is merely a design feature, but the doc will be printed by CMYK:

            – choose such a color and verify by soft proofing that the color is in-gamut for common CMYK spaces. 

            – read the Lab values and proceed as far as possible using Lab.

            – don't use ink names, don't use any reference to Pantone.

            – convert into to a specificic CMYK space in advance to the generation of the specific PDF.

             

            Best regards --Gernot Hoffmann

            • 3. Re: Why can one spot colour convert into two different sets of CMYK values?
              Sitting Giant Level 1

              Thank you both so much for sharing your knowledge!

               

              This helps a lot but also introduces me to a whole new level of understanding the process of colour specification...

               

              Just for clarification, when you suggest 'choose such a color and verify by soft proofing that the color is in-gamut for common CMYK spaces.' is a CMYK space synonymous to a CMYK profile (such as FOGRA32)?

               

              Also when you say 'Assumed, the spot colors are equal by name, but valid for different versions, both in Lab:' - different versions of what?

               

              Appreciating your help, thanks,

               

              Darren

              • 4. Re: Why can one spot colour convert into two different sets of CMYK values?
                G.Hoffmann Level 3

                Darren:

                 

                Common CMYK spaces means:

                Common CMYK printing processes, represented by ICC profiles, like Coated FOGRA or ISOCoated-v2-eci.

                 

                Different versions of Pantone spot colors with the same name, represented by Lab numbers, means:

                Old and new versions, for instance in CS2 and CS6. I don't know the history of all these changes.

                 

                An example, by Photoshop only:

                Coated FOGRA 39 / Relative Colorimetric / Black point compensation

                 

                CS2

                152U: 60L 39a 48b --- 10C 64M 080Y 1K

                152C: 61L 44a 77b --- 05C 65M 100Y 1K

                 

                CS6

                152U: 63L 38a 51b --- 07C 61M 080Y 1K

                152C: 62L 43a 72b --- 03C 64M 100Y 1K

                 

                Best regards ---Gernot Hoffmann