4 Replies Latest reply on May 26, 2015 5:12 AM by BobLevine

    color PDF vs b&w PDF

    left bank books Level 1

      I just made a black and white version of a pamphlet, mainly by making b&w versions of all the photos in it with photoshop. when i exported it to (smallest possible size) PDF, it was surprisingly large (somewhere around 15MB). but then the client asked for a color version, so I reverted to using all the original color photos, and again exported to (smallest possible size) PDF. But this one came out to less than 2MB. Why would this be the case?

        • 1. Re: color PDF vs b&w PDF
          rob day Adobe Community Professional & MVP

          If you were using the default [Smallest File Size] in both cases, that preset does handle grayscale and color images differently:

           

          Screen Shot 2015-04-25 at 7.23.00 AM.png

          It also converts everything to sRGB, so in the end your grayscales get converted back to RGB color. It maybe the effective resolution of your grayscales is just under the 225 threshold?

           

          Also, if you are using CS6 or later you can convert a layout to grayscale on export without converting the images to grayscale in PS first (unless you want to adjust the tonality of the conversions). Something like this in Output:

           

          Screen Shot 2015-04-25 at 7.36.40 AM.png

          • 2. Re: color PDF vs b&w PDF
            left bank books Level 1

            This seems like a good answer, unfortunately I'm trying to export this by doing a "Print Booklet", and doesn't give me the compression option. Also, am I supposed to just change the Bicubic Downsampling to the same as for color?

            • 3. Re: color PDF vs b&w PDF
              rob day Adobe Community Professional & MVP

              and doesn't give me the compression option

               

              When you create a PDF via the print dialog the compression would be handled by the job options setting. On OSX they are set in Distiller, not sure where they are in Windows.

               

              You can also Export form InDesign and use AcrobatPro's booklet printing

              • 4. Re: color PDF vs b&w PDF
                BobLevine MVP & Adobe Community Professional

                Same place, Rob. But as you already pointed out, Acrobat's booklet feature is a far better way to do this.