35 Replies Latest reply on Oct 17, 2015 3:33 AM by rob day

    How can I export to PDF for Offset printing including color and grayscale photo’s?

    SanderDekker

      After reading dozens of forum, I still don’t found the answer.

       

      I made a photobook with full-colur and B/W photos for Offset printing. I want the B/W to be in grayscale to avoid color possible color shades. It seems InDesign doesn’t support grayscale, the images become way to dark. Even with exporting without any colour conversion or destination and/or including original colour profiles, the grayscale pictures are being exported to dark to PDF.


      How can I export to PDF for Offset printing including color and grayscale photo’s?

        • 1. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
          Peter Spier Most Valuable Participant (Moderator)

          Convert your images to Grayscale in Photoshop using the Black Ink channel of the same CMYK color space you use for the color images (and be sure your ID working space is also the same).

          • 2. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
            SanderDekker Level 1

            So I need to copy my grayscale image, change the image to CMYK, paste it in BLACK and clear the C-M-Y layers?

            • 3. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
              SanderDekker Level 1

              If I do it like that, the images becomes lighter...

              • 4. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                Peter Spier Most Valuable Participant (Moderator)

                No.

                 

                InDesign puts Grayscale on the Black plate along with the black channel of CMYK images (as it should, there is no "gray" channel for offset printing). You can create a custom Grayscale profile that uses the Black Ink channel of any CMYK profile. In the color settings dialog, from the Grayscale dropdown choose Load Gray, then choose your CMYK profile:

                LoadGray.png

                • 5. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                  SanderDekker Level 1

                  Sorry to take up all of your time, don't understand why they make it so difficult, but when only using the BLACK layer, the images is getting lighter. Not when only previewing K but it does when saved and CMYK is showing.Example.jpg

                  • 6. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                    Peter Spier Most Valuable Participant (Moderator)

                    The image should be grayscale, NOT CMYK. You use the black ink channel from the CMYK profile to do the conversion to grayscale.

                     

                    In order to do that the first step is to create the gray profile. In Photoshop, Edit > Color Settings....

                     

                    In the dialog open the grayscale dropdown and choose Load Gray and a dialog will open where you should choose your CMYK working profile for the output from ID. When you return to the Color Settings dialog it will now show in the grayscale working space as Black Ink - some CMYK profile. Open the dropdown again and choose Save Gray to save this as a profile you can access. You can cancel out of the color settings dialog, or save the settings to use as a .csf file and set them as the current working space in Photoshop.

                     

                    Open the grayscale image (or a color image) and Edit > Convert to Profile... and choose the new Black Ink - some CMYK profile as the destination for the conversion. It should be at the bottom of the list of available profiles.

                    • 7. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                      SanderDekker Level 1

                      Ok, done all that. After all that it remain a 'grayscale' file right? Not CMYK. Because InDesign keeps on previewing it wrongly. Now when I export the file from InDesign to the CMYK profile it will only send the black layer?

                      • 8. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                        Peter Spier Most Valuable Participant (Moderator)

                        Does the black ink profile match the CMYK working space in ID?

                         

                        When you say ID does not preview it correctly, are you using Overprint Preview or Proof Colors, or just the ordinary preview mode? The latter does not give an accurate output preview. Did you proof colors in Photoshop as well?

                        • 9. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                          rob day Adobe Community Professional & MVP

                          It seems InDesign doesn’t support grayscale, the images become way to dark. Even with exporting without any colour conversion or destination and/or including original colour profiles, the grayscale pictures are being exported to dark to PDF.

                           

                          InDesign doesn't have a grayscale color mode, but it does support placed grayscale objects.

                           

                          So:

                          if you export with No Color Conversion (PDF/X-4), a grayscale object remains as grayscale in the PDF and its output values are unchanged.

                           

                          If you export with the destination as Document CMYK, the grayscale values are transferred unchanged to the black channel of CMYK.

                           

                          The only case where gray values get converted to 4-color CMYK is when you export using Convert to Destination and the destination profile conflicts with the document's profile.

                           

                          InDesign never changes the output values of a grayscale, but it does provide different previews of a placed grayscale. With Overprint or Separation preview turned off you get a "screen" view of a grayscale—if you are designing for web it is gamma 2.2 (or sGray). If you turn on Overprint/Sep Preview you get a print preview—the document's CMYK profile shows you what the gray values will look like when printed on the black plate.

                           

                          In Acrobat if you want the print preview open Output Preview and make sure the simulation profile is your document's CMYK profile.

                          • 10. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                            rob day Adobe Community Professional & MVP

                            Because InDesign keeps on previewing it wrongly.

                            Is Overprint/Separation Preview on or off?

                            • 11. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                              SanderDekker Level 1

                              Yes, the Photoshop & ID CMYK working spaces are the same. The normal preview is way of and when you export to PDF for Offset printing (I have the Dutch one, don't know the exact name of Engels option) without converting to a colour profile, but by using the original image profile, it comes out way to black.

                              • 12. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                Peter Spier Most Valuable Participant (Moderator)

                                Rob is better at explaining this than I am.

                                 

                                I had you convert to the black ink channel of the CMYK profile to be sure that the correct dot gain is being applied since a conversion to a Dot Gain 50 or one of the Gamma gray profiles doesn't necessarily match the dot gain of the CMYK output and press condition and your grayscale images would then output either too dark or too light.

                                 

                                If after you've converted to that profile and checked Proof Colors using the correct profile in Photoshop the photo looks right in Photoshop, it should also look right in overprint preview (and the press output) in ID, as long as you have the correct profile for the press.

                                • 13. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                  rob day Adobe Community Professional & MVP

                                  Yes, the Photoshop & ID CMYK working spaces are the same

                                  This can get difficult because the 3 programs handle soft proofing differently.

                                   

                                  The working spaces don't matter, it's the document profile(s) that manage the preview. So here is the same grayscale image placed in ID on top and PS on the bottom. I've set my Photoshop info to show the doc profile in the lower left corner. I can see my InDesign's Document CMYK profile in my Proof Setup (the Working CMYK is different and isn't being used). Both profiles are effectively the same Coated FOGRA39 (Black Ink FOGRA in the case of PS).

                                   

                                  But the previews don't match because I have Overprint turned off, so the InDesign preview is Gamma 2.2 or a "screen" media preview.

                                   

                                  ScreenSnapz1-3.png

                                   

                                  If I turn on Overprint preview I get a match because I'm soft proofing for print:

                                   

                                  Screen Shot 2015-01-13 at 2.14.22 PM.png

                                  • 14. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                    SanderDekker Level 1

                                    It worked (and I finally understand)! Thanks a lot guys, really appreciate your time. Cheers!!!!

                                    • 15. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                      Roger Breton Level 1

                                      All this discussion would be academic *if* the InDesign development team supported ICC Grayscale color management. According to my discussions at the time with one of the InDesign engineer, responsible for the implementation of color management, this was no big deal. But they never actually committed to doing it. Why? Because it was not a "popular" feature request...

                                      • 16. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                        rob day Adobe Community Professional & MVP

                                        All this discussion would be academic *if* the InDesign development team supported ICC Grayscale color management.

                                        If ID honored gray profiles there would be a new set of output problems to deal with. Currently gray values output unchanged to the CMYK black plate, so the issue is only  how the gray values are soft proofed and doesn't affect output. The preview of a grayscale placed in ID might change from what you see in PS, but the output numbers don't.

                                         

                                        If we could place a grayscale with a profile that conflicted with the document's CMYK black ink profile–something like Dot Gain 20% placed in a layout assigned US Sheetfed Coated—what would happen when we need to export to a final CMYK destination? The conversion of Dot Gain 20% to US Sheetfed Coated would have to be to 4-color CMYK, so on press we would have a 4-color image, which would very likely have unwanted color casts.

                                         

                                        Also Photoshop's curved based gray profiles aren't particularly accurate. The color of the black ink isn't considered the way it is in a CMYK profile. Might not be a problem on a coated sheet, but for uncoated sheets and newsprint you don't want the appearance of black ink to be absolute black because that's never going to happen on press.

                                        • 17. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                          Roger Breton Level 1

                                          If ID honored gray profiles there would NOT be a new set of output problems to deal with.

                                          The problems were addressed at the time and the solutions were not difficult to implement.

                                          It was a lack of willingness on the part of the InDesign team to fix this problem once and for all. Sadly.

                                           

                                          How could a Grayscale ICC profile "conflict" with the document CMYK black ink profile? There is no such thing as a "document CMYK black ink profile".

                                          You guys have convoluted notions of color management.

                                           

                                          I'm sorry. I don't mean to be close-minded.

                                          • 18. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                            rob day Adobe Community Professional & MVP

                                            There is no such thing as a "document CMYK black ink profile".

                                             

                                            In Photoshop you can save and use the Black Ink portion of any CMYK profile as a Gray profile. InDesign uses the document's CMYK profile to soft proof the grayscale which is on the black plate :

                                             

                                            Screen Shot 2015-10-14 at 2.57.57 PM.png

                                            For grayscale work you should use the black ink profile that matches the print destination (which will solve the preview problem). A press can have only one profile so the profile of the black plate can't be both Dot Gain 20% and Black Ink - US Web Coated.

                                             

                                            In Photoshop if you do a conversion from Dot Gain 20% to US Web Coated (SWOP) the result would be a 4-color image. So if InDesign honored the Dot Gain 20% profile embedded in a grayscale image, what would you expect to happen to that image when you export with this setting? RGB and Lab images would get converted to Document CMYK, so why wouldn't the profiled grayscale also get converted?

                                             

                                             

                                            Screen Shot 2015-10-14 at 3.19.43 PM.png

                                            • 19. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                              Roger Breton Level 1

                                              First of all, in Photoshop, it's possible to use genuine ICC Grayscale profiles. These are not readily available but one can generate them as easily as CMYK profiles from publically available characterization data. That's one thing. Why bother with kludges? The Photoshop's generated "Gray" ICC profiles only have one rendering intent, colorimetric. Dumb.

                                               

                                              Second of all, who would ever do a conversion from Grayscale to CMYK in Photoshop? Of course, one would end up with 4-color "blacks", no question..

                                               

                                              Third, InDesign needs to honor Grayscale ICC profiles, period. Upon exporting to PDF, as you know, InDesign does not touch grayscale data, it just passes it unharmed in the output stream. I use grayscale images with embedded profiles all the time in InDesign and the data remains untouched at the time of exporting to PDF or printing ; InDesign does not have any smarts to deal with grayscale appearance. RGB and Lab do get converted to DocumentCMYK, yes, that's a given.

                                               

                                              Grayscale in -> Grayscale out. No changes on output. InDesign is "blind" to any placed grayscale images.

                                               

                                              Softproofing grayscale in InDesign? Why is it so important, don't people softproof grayscale in Photoshop?

                                               

                                              Thank's for your painstakingly well documented screen captures, btw.

                                              • 20. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                rob day Adobe Community Professional & MVP

                                                Second of all, who would ever do a conversion from Grayscale to CMYK in Photoshop? Of course, one would end up with 4-color "blacks", no question..

                                                I do it all the time when I want to print a "quad" neutral image on an offset press. Using all four inks with an extra long black plate will produce more dynamic range on an offset press (richer blacks). But the destination profile has to convert to a heavy black plate in order to prevent color casts.

                                                 

                                                The problem of unexpectedly converting to CMYK is my point, the purpose of a profile is to provide a source for future conversions. In my Export example we are explicitly asking for a conversion to CMYK, so obviously RGB, and Lab will get converted to SWOP. CMYK objects that are tagged with SWOP won't get converted because the source and destination are the same. That leaves us with a grayscale object that has some conflicting profile. How is it to be converted to something other than the chosen CMYK Destination? Unless an exception is added to the Output tab the image would have to export as CMYK.

                                                 

                                                I also used to think we needed a grayscale space, but have come to realize that InDesign's CM would have to get considerably more complex to handle complete grayscale support. Would native gray colors be allowed—would 50% gray and 0|0|0|50 CMYK black be different colors? Would documents now have 3 assigned profiles—CMYK, RGB, Gray. Would 50% gray preview differently than 0|0|0|50 CMYK if the two colors are managed by different profiles. Would there be an exception in the Export Output tab if we need to convert everything to a CMYK destination? I'm sure there's more—that's a lot of complexity to solve a fairly minor problem.

                                                • 21. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                  Roger Breton Level 1

                                                  Good point, converting from Grayscale to CMYK to get a "quad" neutral image.

                                                   

                                                  First of all, unless you use a heavy GCR profile, good luck getting satisfactory "neutrals" off an offset press using this technique, unless you are not too demanding. And even there. A Destination profile with a heavy black plate is not enough in many cases, you need no CMY in the range L100 down to L30, with a progressive introduction of CMY in order to hedge your bets on press. Believe me.

                                                   

                                                  Reading further your comments, you seem to believe that, somehow, InDesign *does* something with grayscale data and that has something to do with the DocumentCMYK profile? Create confusion? Let me insist : there are no conversions whatsoever involved when InDesign encounters grayscale data on output. Your statement that the grayscale image "would have to export to CMYK" is incorrect. There is no unexpected conversion taking place? Try this for yourself :

                                                   

                                                  • Create grayscale image in Photoshop and assign it the ICC profile of your choice
                                                  • Place in InDesign
                                                  • Export to PDF, convert to your choice of Destination profile in the Output tab
                                                  • View in Acrobat's Output Preview

                                                   

                                                  I dare you find any differences between the dot percentages in Photoshop and those in Acrobat. There isn't.

                                                   

                                                  Too bad you seem to believe that adding an ICC Grayscale color management option to InDesign CMS capabilities would make the application considerably more complex. I don't know where you got that idea. Just talk to Matt Phillips in the InDesign's development team. He'll straighten you out. I might still have his original correspondance on file on the subject...

                                                  • 22. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                    rob day Adobe Community Professional & MVP

                                                    • Export to PDF, convert to your choice of Destination profile in the Output tab

                                                     

                                                    I dare you find any differences between the dot percentages in Photoshop and those in Acrobat. There isn't.

                                                     

                                                    Ok, if the destination profile doesn't match the document CMYK profile you'll get CMYK. Like this from a document assigned with SWOP:

                                                     

                                                    Screen Shot 2015-10-15 at 7.43.15 AM.png

                                                     

                                                    gracol.png

                                                     

                                                    I understand that when the export is to DocumentCMYK or No Color Conversion, grayscales go out as DeviceGray and there's no value change.

                                                     

                                                    If you are preparing a job for offset printing, the grayscale values don't output to a separate gray plate, they output to the K plate.

                                                    So consider this where I have a Dot Gain 15% Grayscale document filled with 50% gray, and a US Sheetfed CMYK doc filled with 0|0|0|50:

                                                     

                                                    Screen Shot 2015-10-15 at 8.01.32 AM.png

                                                     

                                                    Which preview of 50%K (or gray) is correct? If we make the assumption that it's the final US Sheetfed destination, we would need to make a conversion to adjust the numbers in the Dot Gain 15% grayscale. What would the destination profile be? It would have to be Black Ink US Sheetfed and that's easy enough to do in Photoshop—the conversion is to 37%:

                                                     

                                                    Screen Shot 2015-10-15 at 8.50.50 AM.png

                                                    If InDesign's Color Settings had a Gray Working space would you allow the user to choose Dot Gain 15% and use US Sheetfed Coated as the CMYK Working Space and have 50% gray previewing differently than 0|0|0|50 CMYK?

                                                    • 23. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                      Danny Whitehead. Level 4

                                                      Ok, if the destination profile doesn't match the document CMYK profile you'll get CMYK. Like this from a document assigned with SWOP:

                                                      Wouldn't that be a case for including proper greyscale CM in ID, so they're converted to the black plate of the destination CMYK?

                                                       

                                                      If InDesign's Color Settings had a Gray Working space would you allow the user to choose Dot Gain 15% and use US Sheetfed Coated as the CMYK Working Space and have 50% gray previewing differently than 0|0|0|50 CMYK?

                                                      That's a good point, but I'm not sure ID would need a working/assigned grey profile. It could still use the black plate of the the assigned CMYK profile. It would convert placed greyscale images to that space, and if you export to different destination, convert to that black plate.

                                                      • 24. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                        rob day Adobe Community Professional & MVP

                                                        That's a good point, but I'm not sure ID would need a working/assigned grey profile. It could still use the black plate of the the assigned CMYK profile. It would convert placed greyscale images to that space, and if you export to different destination, convert to that black plate.

                                                         

                                                        Yes, I think full grayscale CM with a working space, assigned profiles, and native grayscale swatches would be a nightmare for users who are already struggling with CM. You you are right, tagged grayscales could silently be converted to the CMYK black ink profile. In my example the 50% gray would output as 37% to maintain the appearance. But I promise you there would be users who are correcting by the numbers screaming about the value change over in Acrobat.

                                                        • 25. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                          Roger Breton Level 1

                                                          A "full grayscale CM with a working space, assigned profiles, and native grayscale swatches would be a nightmare for users who are already struggling with CM" would not be anymore of a nightmare to users than working with RGB and CMYK working spaces and assigned profiles. Color management isn't that hard. My students and clients always get it after some basic walkthroughs. There is no need to manage grayscale through the DocumentCMYK on output, gray remains gray.

                                                           

                                                          About "the black plate of a CMYK profile". There is no such thing, a CMYK profile does not have a "separate black plate". Photoshop is able to build a grayscale profile on the fly from a selected RGB or CMYK profile by reading the CIE Lightness scale. There is no other way to do this through the Tags contained in an ICC profile.

                                                          • 26. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                            rob day Adobe Community Professional & MVP

                                                            Photoshop is able to build a grayscale profile on the fly from a selected RGB or CMYK profile by reading the CIE Lightness scale.

                                                            You can only load a CMYK or Gray profile, if you try to load an RGB profile you'll get an error. You can then save the Black Ink profile via Gray>Save Gray and use it for conversions and assignments.

                                                             

                                                            Screen Shot 2015-10-15 at 2.10.23 PM.png

                                                             

                                                            If you assign Black Ink - US Sheetfed Coated v2 to a grayscale and place it in an ID document with a US Sheetfed Coated v2 CMYK assignment, the previews in Photoshop and ID will match when you turn on Overprint or Separation Preview.

                                                            would not be anymore of a nightmare to users than working with RGB and CMYK working spaces

                                                            So you don't think it would be a problem if 50% gray previewed differently than 0|0|0|50 CMYK?

                                                            • 27. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                              Roger Breton Level 1

                                                              Correct. My bad. That "Load Gray..." is only able to retrieve the needed information out of a CMYK profile but it could be had out of an RGB profile too.

                                                               

                                                              You're the one who wrote yesterday that "softproofing should have already happen within Photoshop, before the image is placed in InDesign".

                                                              A "Black Ink - CMYK profile" is a poor man Grayscale profile.

                                                               

                                                              If I need a Grayscale GRACoLprofile, I can make one that will preview 50% gray on par with a 0c0m0y50k CMYK.

                                                              • 28. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                rob day Adobe Community Professional & MVP

                                                                If I need a Grayscale GRACoLprofile, I can make one that will preview 50% gray on par with a 0c0m0y50k CMYK.

                                                                Exactly my point. I don't think you would see any practical difference between your profile and a Black Ink - GRACol profile. If there was an ID gray space and you didn't use GRACol as the Gray assignment you would have the same gray and Black values previewing differently. I don't see how that's not a problem.

                                                                • 29. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                  Roger Breton Level 1

                                                                  There are two parts to any output profile. The "proofing" part, B2Ax (Device to PCS), and the "matching" part, A2Bx (PCS to Device).

                                                                  In principles, any Grayscale ICC profile drawn from the same characterization data should be identical as far as the Device to PCS direction is involved.

                                                                   

                                                                  With Adobe's supplied CMYK profiles, I can witness that this is indeed the case. With "Black Ink" profiles, I don't know, I haven't spent the time to trace down what they do..

                                                                   

                                                                  In general, I don't mind using Adobe's profiles for "proofing" but not for "matching" (converting). I don't like the way the lock users into one style of conversion no matter what rendering intent is selected in the ConvertToProfile dialog box. I understand their reason for doing so but that's no my cup of tea.

                                                                   

                                                                  Having said that, if InDesign had a Gray space "working space" and a user didn't use a matching Grayscale / CMYK defaults and assignments, we would have much to say about the comparative appearances of gray elements in both kinds of images. Provided "Preseve Numbers" is not selected in ColorSettings, then each image's embedded profiles will become the Source in the profile conversion to the screen. We could debate this at length and there are many approaches to solve what seems to you like an impossible scenario. 

                                                                  • 30. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                    rob day Adobe Community Professional & MVP

                                                                    there are many approaches to solve what seems to you like an impossible scenario

                                                                    Ok tell us what the solution would be for the mismatched appearance of same values?

                                                                    • 31. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                      rob day Adobe Community Professional & MVP

                                                                      Take percentages out of the mix, here's 100% gray assigned with the default Dot Gain 20% and 100% Black 0|0|0|100 with Uncoated GRACol:

                                                                       

                                                                       

                                                                       

                                                                      gracol.png

                                                                       

                                                                      Which of the two is the best representation of what will happen on press?

                                                                      • 32. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                        Roger Breton Level 1

                                                                        Your comparison is relevant but you obviously don't know colorimetry -- no offense.

                                                                         

                                                                        Try this, using the Color Picker. Bring up the Info palette (F8). On the left hand side, select Grayscale. On the right hand side, select Lab.

                                                                        Then, position the ColorPicker over the 100% Grayscale window. You get 100% K but what is the Lab reading? See? That's Adobe for you.

                                                                        • 33. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                          rob day Adobe Community Professional & MVP

                                                                          The Lab values match the appearance.

                                                                           

                                                                          I get 0|0|0 for the grayscale 100% and 15|2|9 for the CMYK Black 100%.

                                                                           

                                                                          The 0|0|0 grayscale preview in Photoshop is not accurate. If you've ever been on press printing on an uncoated sheet you know that 0|0|0|100 is not absolute black and should not display that way.

                                                                          • 34. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                            Roger Breton Level 1

                                                                            Lab = 0,0,0 for the grayscale is correct.

                                                                            Lab = 15,2,9 for your Uncoated GRACoL is wrong.

                                                                            100% Black on Coated GRACoL is 15,0,0 and should be 32,0,0 for Uncoated GRACoL.

                                                                             

                                                                            The 100% Black Grayscale preview in Photoshop *is* accurate.

                                                                            You have to understand a little more about ICC profile and Photoshop's ICC implementation to figure out why.

                                                                             

                                                                            You think I never been on press? I professionally calibrated and profiled more presses than you can ever approach in your lifetime. Presses, proofers, monitors, ...

                                                                            • 35. Re: How can I export to PDF for Offset printing including color and grayscale photo’s?
                                                                              rob day Adobe Community Professional & MVP

                                                                              You think I never been on press? I professionally calibrated and profiled more presses than you can ever approach in your lifetime. Presses, proofers, monitors, ...

                                                                              Cool.

                                                                               

                                                                              And you've never noticed that 100K+CMY has a different appearance on press than 100K? You can insist that 100% grayscale correctly previews as 0|0|0, but it won't magically print as rich black on press.