10 Replies Latest reply on Jun 12, 2008 7:38 AM by

    colour conversion on export - its a toughy

      Hi Sorry about the crosspost, but I had no joy in the indesign forum:

      this is a problem with a CMYK document, with CMYK images (mostly with no profile attached).

      I have a printer that will reject anything with colour density greater than 300%. Usually I output safe files from photoshop, but didn't on this job. It'll take me ages to go back and convert the placed content in photoshop so...

      I've just spent an hour fiddling with colour conversion and export presets to try to get indesign to convert the placed content only.

      I thought I'd cracked it, but realised that indesign had also converted my 100%K text to rich black.

      Heres what I did:
      export>output>
      convert to destination
      US WEB COATED (SWOP) v2
      dont include profiles (printer uses an unmanaged workflow)

      problem is that also converts the text. So I tried
      convert to destination (preserve numbers), which didn't do anything to the placed content. So I then tried converting the whole document to different profiles and converting to those profiles on export (thinking that indesign would convert the placed conent as their profiles should not have been convereted), but nothing worked here either.

      Anyone know a way to export from indesign to control ink densities, without altering my straight blacks?
      thanks!

      Gethin
        • 1. Re: colour conversion on export - its a toughy
          Rather use
          - color conversion in Acrobat 8 Pro (or soon in 9 Pro)
          - dedicated tools, like pdfToolbox' pdfCOlorConvert (that's our/callas' tool)
          - or dedicated tools from other vendors, like Heidelberg's color conversion plug-in (I have lost track of what it's current product name is, but it is a professional tool as well)

          There, in Acrobat/with your PDF(s) you have much more fine grained control. And you will grow less gray hair.

          Olaf Druemmer
          callas software

          PS: Hint -at least pdfToolbox can be used 30 days for free, download at www.callassoftware.com (now you know why I am not in sales...)
          • 2. Re: colour conversion on export - its a toughy
            Gusgsm Level 2
            <em>It'll take me ages to go back and convert the placed content in photoshop so...</em><br /><br />Even with a Photoshop action CMYK - Lab/RGB - CMYK and batch proccessing and afterwards a massive link updating?<br /><br />Unless you have text in those picures...<br /><br /><insert doubt icon here>
            • 3. Re: colour conversion on export - its a toughy
              Gethin,

              I've done a fast test for a PDF by Acrobat7 Prof.:

              Tools / PrintProduction / Convert Colors / CMYK
              X Preserve Black Objects

              The original space in the PDF was ISOCoated, the
              new space is Euroscale Coated. Black text is K-only.
              Seems to work, but you may test it again.

              Best regards --Gernot Hoffmann
              • 4. Re: colour conversion on export - its a toughy
                Level 1
                Gernot
                that should've worked (great tip by the way, hadn't occurred to me to use acrobat), but when I exported the pdf as the same colour space as indesign and converted it it doesn't seem to do much to what was placed images. I tried loads of different combinations of colour spaces. When it DID work it wouldn't treat the areas of the PDF that had been transparency flattened in the same way as the rest of it.

                Gustavo - looks like its my only option Trouble is I hate going back to RGB from CMYK and back again. It means each image would've been converetd 3 times (rgb-cmyk-rgb-cmyk!).
                • 5. Re: colour conversion on export - its a toughy
                  Lou Dina Level 3
                  Gethin,

                  Not sure if this will work or not, but it is worth a try.

                  First, assign the appropriate profile to your placed images. If they have a profile attached, they won't be converted per the following steps.

                  Next, assign your destination profile to the entire document. This will affect all native InDesign components. It also affects all placed documents that don't have a profile tag, which is why we assigned a tag above.

                  Now, if you convert the entire document to your destination profile, your InDesign components should remain unchanged, since we previously assigned the same profile to them. This should keep the black text and all black components on the K plate only. As long as the images have a separate tag, this should not affect them. You may want to check though.

                  At this point, you can create a PDF and check to be sure your images have the proper tags and that your native components are correct, including black text all on the black plate.

                  That or some variation should work.

                  Lou
                  • 6. Re: colour conversion on export - its a toughy
                    Level 1
                    Olaf, I missed your post at first
                    it works!
                    I used the option to limit ink to 300%.
                    Now the question is - why doesn't my printer have this (seeing as its 400 euros, and they'd be using it everyday, wheres I'd need it once a month at best!) If it was $300 AUD (about 200 euro) i would consider it (how about a stipped down version without the layer-making?)

                    very nice bit of software!

                    gethin
                    • 7. Re: colour conversion on export - its a toughy
                      Gethin,

                      My recommendation: no sophisticated workflows - just PDF/X-1a.
                      A. Standard:
                      1. Use a global CMYK space, here ISO Coated.
                      2. Convert all images in Photoshop.
                      3. Make document in InDesign.
                      4. Flatten and check the result (PDF/X-1a joboption flattens
                      anyway).
                      5. Export as PDF with Leave Color Unchanged (same numbers).
                      6. Don't embed profiles. But the profil is mentioned as
                      rendering intent (an optional information, required
                      for PDF/X-1a.
                      B. Modify for new profile:
                      1. Check whether the global space is still (here) ISO Coated.
                      2. Convert into other space, for instance Euroscale Coated
                      as explained above.
                      3. Now it would be necessary to replace the rendering intent
                      information.
                      4. Save As with new name.

                      Workflow A is fully tested, also with proof printing by inkjet.
                      Workflow B was partly tested.

                      Best regards --Gernot Hoffmann
                      • 8. Re: colour conversion on export - its a toughy
                        Level 1
                        HI Lou,
                        thanks for you post, but if I understand correctly you are saying your method should not effect placed content, but it is the placed content I want to effect! (As I didnt convert the original images to a ink-density-safe colour space, I was hoping to do that in indesign.

                        Gernot, thanks - same problem - brings me back to changing converting all photos in photoshop again (or are you saying that I just need to attach a profile to all of them - ie to go to CMYK no profile to CMYL iso coated)?

                        thanks!
                        • 9. Re: colour conversion on export - its a toughy
                          Lou Dina Level 3
                          Gethin,

                          Sorry....I must have misread what you wanted.

                          If you have UNtagged CMYK images in your document, they will be treated the same as native InDesign components. So, in this case, if you "assign" a profile to your document, such as US Web Coated SWOP, all your images will now assume that profile, and should look "as if" they were printed on a device that conforms to US Web Coated SWOP. In order words, the look may change.

                          Of course, this cannot correct the original files and adjust the ink limits, since they are individual files outside of InDesign. But using Acrobat or similar program, you can convert to PDF using the desired profile and it should correct ink limits to the new destination during PDF creation. It's been awhile since I did this.

                          Lou
                          • 10. Re: colour conversion on export - its a toughy
                            Gethin,

                            hopefully you'll understand that it's hardly possible
                            to describe such a complex workflow in one or two posts.
                            Nevertheless, the concept is correct, IMO.

                            Here comes the whole workflow for PDF/X-1a and a global
                            change of the CMYK space in the PDF.
                            Replace ISO Coated (old) and Euroscale Coated (new) by
                            your profiles.

                            Neither single CMYK images nor the PDFs have embedded
                            CMYK profiles.

                            Settings in CS2:
                            RGB = sRGB
                            CMYK = ISO Coated
                            Gray = Black Ink ISO Coated (instead of dot gain)
                            Spot = Black Ink ISO Coated (instead of dot gain)
                            Synchronize by Bridge, check in Acrobat explicitly

                            Settings in Photoshop:
                            RGB: Convert to working RGB
                            CMYK: Preserve embedded profiles [read context help !]

                            Settings in InDesign:
                            RGB: Convert to working space
                            CMYK: Preserve numbers (ignore linked profiles)
                            [read context help !]
                            Preparations in Photoshop:
                            Convert images to CMYK and save without profile
                            anne-untagged-iso.tif

                            Make new doc anne.innd in InDesign:
                            Place anne-untagged-iso.tif
                            There is no mismatch, therefore no question
                            Write some text by black (K-only)

                            Preparations for Export To PDF, during the first Export:
                            Use Joboption PDF/X-1a 2001 as a template and modify:
                            Resolution color 288ppi if above 288ppi
                            Compression none
                            Resolution gray 288ppi if above 288ppi
                            Compression none
                            Output:
                            Convert to destination (preserve numbers)
                            [read context help - no mismatch, no conversion !]
                            Destination: ISO Coated
                            Output Intent: ISO Coated
                            Save settings as PDF/X-1a 288-UnComp-ISO

                            Export as anne-iso.pdf

                            Check by Tools / Print Production / Output preview:
                            Black text is K-only

                            Check by Tools / Print Production / Preflight / PDF/X-1a:
                            File is compatible
                            Color space is Device CMYK (not detected as ISO Coated !)
                            Output intent is ISO Coated

                            If necessery convert into other CMYK space, here Euroscale
                            Coated:
                            Tools / Print Production / Convert Color / Convert CMYK
                            Destination space: Euroscale Coated v2
                            yes Embed Profile as Output Intent
                            yes Preserve Black Objects
                            Execute
                            Save as anne-euro.pdf

                            Check by Tools / Print Production / Output preview:
                            Black text is K-only

                            Check by Tools / Print Production / Preflight / PDF/X-1a:
                            File is compatible
                            Color space is Device CMYK (not detected as Euroscale Coated !)
                            Output intent is Euroscale Coated v2

                            Should be corrected if still buggy !

                            A very dangerous style is IMO the profile assignment per
                            object. I'm preferring unique global definitions.

                            Best regards --Gernot Hoffmann