4 Replies Latest reply on Feb 17, 2014 4:04 AM by RE:TOUCH

    UCR/GCR in neutral/gray/B&W parts of an image

    RE:TOUCH Level 1

      Hello,

       

      Although im kind of familiar with the term and uses of UCR/GCR, I have been asked by a client for the follwing and was wondering if anyone can advise how best to handle this?

       

      The job I am working on is a jewellery shoot - so the have a mixture of gold and silver as well as colored stones, gems etc..

       

      This is what is being request for each image.

       

      - The max density should be around 320, no lower than 300 dmax.
      - Neutral (gray or BW) areas of shot (i.e., neutral elements on jewellery , or neutral
        backgrounds) to have UCR/GCR (3 color removal) applied specifically so that

        color does not swing on press.

       

       

      My normal process is a straight conversion from RGB to CMYK, which has always proved fine with no issues.

       

      But with the above requests, after finishing the retouching, what should be the next process to achieve them?

       

      Thanks in advance for any advice and info.

        • 1. Re: UCR/GCR in neutral/gray/B&W parts of an image
          thedigitaldog MVP & Adobe Community Professional

          This might help:

          http://digitaldog.net/files/CMYKPart2.pdf

           

          Frankly, the last thing you want to do is be in charge of a CMYK conversion if you're not provided the exact recipe for the press output! There is no such thing as a 'straight conversion' every device requires a different recipe of CMYK and the incorrect recipe can produce real headache’s on press.

           

          http://www.ppmag.com/reviews/200703_rodneycm.pdf

          • 2. Re: UCR/GCR in neutral/gray/B&W parts of an image
            G.Hoffmann Level 3

            This quote

            Neutral (gray or BW) areas of shot (i.e., neutral elements on jewellery , or neutral
            backgrounds) to have UCR/GCR (3 color removal) applied specifically so that

            color does not swing on press.

            means in my opinion: remove as much of equal amounts C,M,Y and replace by K in order

            to stabilize the print and to reduce the ink percentage. That's called UCR if done only

            in neutral areas and GCR if done everywhere. GCR comes light, medium and heavy.

            A 'straightforward conversion" according to the recommendations of the printing people,

            using an ICC profile which is appropriate for the process and the paper, is absolutely correct,

            for instance SWOP or ISOCoated-v2-eci. The specific GCR belongs as part of the process

            to the profile.

             

            I read as well the inquiry in the Photoshop Forum. In my opinion it's clearly a misunder-

            standing, that neutral areas should be printed by K-only. It would be nonsensical, because

            K-only cannot create neutral D50 gray on arbitrary paper. Furtheron the transitions between

            neutral areas and almost neutral areas would be very wrong.

             

            Best regards --Gernot Hoffmann 

            • 3. Re: UCR/GCR in neutral/gray/B&W parts of an image
              D Fosse Adobe Community Professional & MVP

              G.Hoffmann wrote:

               

              In my opinion it's clearly a misunderstanding, that neutral areas should be printed by K-only.

               

              Yes, I'm fully aware of that, and I assumed my initial reply made that clear. It was merely an "emergency workaround".

               

              Anyway, thanks for confirming, and so I think there is a consensus. With the correct profile the request makes little sense.

              • 4. Re: UCR/GCR in neutral/gray/B&W parts of an image
                RE:TOUCH Level 1

                Thank you.

                 

                I have posted back in the photshop forum too.

                Essentially, the client took control of this process and i just handed them masks for each image.

                 

                Like you say, I assume theyhave simple removed equal amounts fo C,M,Y on the GRACol file.

                 

                I rached out to quite a few people regrading this and its seems everyone had the same conclusion which was "a pointless exercise"

                 

                The client, however felt this was necessary for the project.