3 Replies Latest reply: May 24, 2013 3:14 AM by Mylenium RSS

    CMYK Conversion

    Jim_Palik Community Member

      I recently photographed a set of pastels in raw. The body of work has been reviewed and the final color balance has been approved by the artist. I now need to export the images from their raw files to CMYK. to provide for offset printing. Adobe provides a number of options. I am completely lost on the options to select. Can you help me?

       

      The Source Space is Adobe RGB 1998

       

      The Color Space Conversion Options are:

       

      Conversion Options

       

      Engne:

          Adobe (ACE)

          Microsoft ICM

          Adobe CMM

       

      Intent:

          Perceptual

          Saturation

          Relative Colorimetric

          Absolute Colorimetric

       

      Selections with Selection Boxes

          Use Black Point Compensation

          Use Dither

       

      And, of course there is a CMYK Set of selection options that I assume are based on the paper the printer will use.

       

      Do you have a recommendation on the Engine, Intent, Black Point, and Dither.

       

      Thank you

        • 1. Re: CMYK Conversion
          Mylenium MVP

          Don't mess with any of that until you have inquired with the people who do the actual printing what they actually want! By default PS uses a ICC/ISO/FOGRA compliant setting and that works 95% of the time, but it may still require to know the actual specs and color profiles for the print job with respect to ink density and paper properties, especially since you speak of pastels, which means it could operate on the edge of the lowest possible ink densities and colors may need further tweaking to compensate. Again, don't rush into action before you haven't figured out what the print facility wants. At best export a sample file and send it to them, then let them verify and soft-proof or even control yourself on their equipment by giving them a visit...

           

          Mylenium

          • 2. Re: CMYK Conversion
            Jim_Palik Community Member

            Hello Mylenium,

             

            Thank you for your reply,

             

            1. Can you give me some information about you and your background wiht offset printing? You sound knowledgeable.

             

            2. Can you help me with the settings I should use for Engine, Intent, and Black Point Compensation. Or, are these settings also determined by the person doing the printing?

             

            3. Last but not least, should I be providing 8 or 16 bit images.

             

            Thank you again,

             

            Jim

            • 3. Re: CMYK Conversion
              Mylenium MVP

              I'm not that terribly knowledgeable at all in these areas, actually; they're really just random bits and pieces I learned over time from others and through what little work we do on that end (one of our clients is actually a print machine manufacturer, so you see the connection... ) Regarding the color conversion, just leave everything as it is. Use the Adobe engine and use Relative Colorimetric. It does all the necessary technical tricks. One would e.g. only use Perceptual, if a specific printing process got involved and/or you would want to create/ retain a very specific color by doing further adjustments in CMYK mode. Black point compensation should always be used to produce the correct "rich blacks" or in reverse, avoid oversaturating your dark colors and muddying your other colors. Again one would only turn this option off if you planned to extensively manually mangle your CMYK file and thus tweak the resulting densities. Whether or not you provide 16bit images depends on the image content and how you print it. Generally the gamut of CMYK work is nowhere near 16bit, but some facilities can use the extended color range to produce extra separations e.g. for inkjet printing with more than the 4 CMYK inks that produce finer tones. It's mostly irrelevant for mass offset printing, though, so using 8bit files will do just fine. It's really more critical to not introduce any clipping or other artifacts during the conversion.

               

              Mylenium