4 Replies Latest reply on Nov 24, 2010 7:09 AM by Rick McCleary

    Conversion to CMYK prints tinted images - how do I avoid this?

    GarethButterworth

      Hi guys,

       

      I'm having trouble with some images I need printing. I have taken a lot myself but have also received some photos from manufacturers, they are all to go in a gift catalogue. Now the images I have been sent are fine and come out as expected (they are jewellery pieces so have a lot of silver and white metal in the images) with greys looking grey, but when mine are printed they come out with a yellow or slightly pinkish tint. I am printing in indesign and noticed when the images convert from RGB (where they look fine) to CMYK they get this tint. I have gone into photoshop and converted some to CMYK seperately but when I do this they also appear tinted, even totaly desaturating the images they still look tinted - for example using the colour picker on what should be greyscale when I've desaturated the image I get this colour:

       

      #aea19c

       

      C - 32%

      M - 32%

      Y - 32%

      K - 9%

       

      R -174

      G -161

      B - 156

       

      Which looks a bit pinkish to me.

       

      Do anybody have any advice they can give me?

       

      Kind regards,

       

      Gareth

        • 1. Re: Conversion to CMYK prints tinted images - how do I avoid this?
          John Danek Level 4

          There sometimes is or are color casts working with some sRGB originals.  Are the images sRGB or what RGB profile is the original given, if any?  Try copying the original file in Photoshop.  Open the copy and when it asks you what profile to assign the pic, choose Adobe RGB or assign it when the file is open.  Then, convert the Adobe RGB to CMYK and see what happens.  A CMYK file with 32c, 32m, 32y, and 6k is a good gray and should not show a cast.

          • 2. Re: Conversion to CMYK prints tinted images - how do I avoid this?
            p_d_f Level 2

            "I'm having trouble with some images I need printing. I have taken a lot myself but have also received some photos from manufacturers, they are all to go in a gift catalogue. Now the images I have been sent are fine and come out as expected (they are jewellery pieces so have a lot of silver and white metal in the images) with greys looking grey, but when mine are printed they come out with a yellow or slightly pinkish tint. I am printing in indesign and noticed when the images convert from RGB (where they look fine) to CMYK they get this tint."

             

            First of all, you need to check these images in Photoshop to make sure they are actually neutral and adjust as needed before placing in InDesign. You need a combination of a calibrated display and you need to read the numbers - remember that in RGB, when all three numbers are equal, it has to be neutral. If you're printing out of ID, you need to make sure you are using the right profiles for your output. What is your output in this case. If you're printing to an in house inkjet, you probably don't want to send CMYK and if you are, that may be part of the problem. If you are proofing to your printer's (where you catalogue in being printed) proofing system, then CMYK is most likely preferred, but it has to be the right version of CMYK for that printing house. The wrong CMYK can definitely cause color shifts.

             

            "I have gone into photoshop and converted some to CMYK seperately but when I do this they also appear tinted, even totaly desaturating the images they still look tinted - for example using the colour picker on what should be greyscale when I've desaturated the image I get this colour:"

             

            You can desaturate and RGB image, but you can't desaturate CMYK and get neutral. If you try to desaturate CMYK you get what you got - Cyan, Magenta and Yellow numbers that are equal. That will almost always make a reddish neutral. The Cyan component has to be several points higher than the others to achieve a good neutral. The previous advice you got was unfortunately wrong. The RGB numbers you posted would indicate a reddish-yellow tint to the neutral - Red high than Green and Blue lower than Green - so it's no surprise if that combo made a warmish color as well.

             

            What you are trying to do is easily doable, but you probably need to spend some time learning some digital color and offset printing basics. Some of it is counterintuitive at first, especially the fact that equal amounts of Cyan, Magenta and Yellow do not make neutral while equal amounts of Red, Blue and Green do. Entire books have been written about that.

             

             

             

            C - 32%

            M - 32%

            Y - 32%

            K - 9%

             

            R -174

            G -161

            B - 156

             

            Which looks a bit pinkish to me.

             

            Do anybody have any advice they can give me?

            • 3. Re: Conversion to CMYK prints tinted images - how do I avoid this?
              Rick McCleary Level 3
              ... I have gone into photoshop and converted some to CMYK seperately but when I do this they also appear tinted, even totaly desaturating the images they still look tinted - for example using the colour picker on what should be greyscale when I've desaturated the image I get this colour:

               

              C - 32%

              M - 32%

              Y - 32%

              K - 9%

               

              Gareth -

               

              What method did you use to desaturate the images?

               

              Looking at the CMYK values you've offered, I would guess that you went in and manually set the C, M, Y values to match one another. In a standard RGB working space (like sRGB or AdobeRGB98), this makes sense: when the R, G, B values match, there is no color/saturation. However, as p_d_f pointed out, this is not how CMYK works. A neutral no color/no saturation formula for CMYK will almost always be M = Y and C a bit higher. Color management tools in the standard workflow will handle this automatically. The key is in understanding the concepts underlying color management.

               

              Perhaps we can help your specific issue if you give us details about how your color management is set up. In Photoshop, look in Edit>Color Settings. Make a screen shot of that window and post it here. We can go from there.

               

              Thanks!
              RIck

              ___________________________

               

              author

              CMYK 2.0: A Cooperative Workflow for Photographers, Designers, and Printers

              a Peachpit book

              • 4. Re: Conversion to CMYK prints tinted images - how do I avoid this?
                thedigitaldog MVP & Adobe Community Professional

                GarethJB84 wrote:

                 

                I have gone into photoshop and converted some to CMYK seperately but when I do this they also appear tinted, even totaly desaturating the images they still look tinted

                First things first, what CMYK ICC profile are you using to do the conversions, is this a profile that you know is based on the actual printing conditions or better, the contract proof?

                 

                Providing CMYK values is kind of meaningless when every CMYK device could produce differing values based on their conditions, inks, papers etc. Lets start with the idea that the conversions are being optimized for the actual print or contract proofing conditions, then maybe talk numbers.