19 Replies Latest reply on Jul 15, 2009 11:22 PM by Laurens Leurs

    What is PDF/x-4?

    JustBob Level 1
      Okay, I see ID CS3 exports PDF/x-4 files; but, documentation is skimy or non-existent, it seems. Can anyone tell me how this standard differs from PDF/x-1a and PDF/x-3. I kow x-1a exports CMYK files and x-3 exports a mix of cmyk and rgb. But, x-4? What does it do?
        • 1. Re: What is PDF/x-4?
          Level 1
          The PDF/X standard is a subset of PDF that focuses on "blind exchange" of prepress data. Each "flavor" of PDF/X is designed to address the needs of different workflows or users.

          * PDF/X-1a supports CMYK and Spot color. This is the common choice in the US, where most printers aren't color management savvy.
          * PDF/X-3 supports full color management based on ICC profiles and device independent color. It is the common choice in Europe, where the printers are more concerned about color fidelity.

          Both of these are based on PDF 1.4, but without live transparency. In order to address modern PDF workflows where the need to keep transparency live is important for high fidelity output as well as other newer features of PDF (like Layers), PDF/X-4 was created. It is based on PDF/X-3 and full color management.

          Hope that helps.
          • 2. Re: What is PDF/x-4?
            JustBob Level 1
            Thank you, Leonard. That is very helpful. I wish my US printers were X-3 savy, then I could send them X-4 files. But, none of the ones I use have in-RIP separations. I am under the impression that is what is necessary to process X-3, and, I suppose, X-4 files. So, I guess I am stuck with X-1a.
            • 3. Re: What is PDF/x-4?
              Dov Isaacs Adobe Employee
              In-RIP separations is a separate issue from which PDF/X you use. PDF/X-1a is a composite color workflow where separations are made somewhere. If not in the RIP, your printers must be doing the separations in Acrobat. And if they are using any recent version of Acrobat, they should (famous last words) be able do deal with PDF/X-3 or PDF/X-4.

              By the way, it is exceptionally unusual for any printer these days not to be doing separations in the RIP itself!!

              PDF/X-4 is at this point a draft ISO specification. The ISO committee working on PDF/X-4 has approved the specification, but ISO has yet to do final editorial work and publish the specification. We expect that publication (along with PDF/X-5) to occur early Autumn.

              - Dov
              • 4. Re: What is PDF/x-4?
                What is your opinion: is PDF/X-4 really a chance to get higher fidelity for output systems in an pdf-workflow or do you think PDF/X-4 can also cause many problems in prepress because of live transparency?
                What do you really think about the future with PDF/X-4 and what are your experiences?

                Than you for your opinion!
                • 5. Re: What is PDF/x-4?
                  JustBob Level 1
                  You know, I don't know about PDF/X-4; but, I did have one experience I think was related to transparency.

                  We printed a business cards that had a fairly small logo indicating the business location on a map. There was a wavy red line over a fat blue "M". I sent a PDF/X-1a file specifying the default (I think) version of Acrobat to use; one that flattened transparency. The red line nearly disappeared. I thought the problem was improper trapping, but the printer said that wasn't the case.

                  I made a new PDF file, this time using the newest version of Acrobat, one that is supposed to support transparency. Voila! Nice red line. (See, the logo was in an illustrator file, one using transparencies and effects. The logo was them placed inside an InDesign doc. I guess Adobe knows the details about flattening...)
                  • 6. Re: What is PDF/x-4?
                    Dov Isaacs Adobe Employee
                    I don't think that many out there can talk about their real life experiences with PDF/X-4 since the standard hasn't been officially published yet.

                    What one can talk about is whether maintaining content at the highest level of abstraction will cause improvement or deterioration in quality of printing and in the lives of those involved with prepress and printing.

                    The fact is that any print service provider that requires their customers to pre-flatten any transparency is not really avoiding problems, but rather causing problems. In order to properly pre-flatten live transparency, one must know the resolution of the device the content is being imaged to as well as its color space. Who is more likely to know this information and how to apply it, the creative professional or the print professional? Any PDF file created with pre-flattened transparency is by definition highly device-dependent in terms of resolution and color space. Such PDF files are difficult if not impossible to search and/or apply touch-up operations to. Yes, it is true that for older pre-press workflows that don't support PDF 1.4 and above, having the customer flatten the transparency saves the print service provider one step. On the other hand, although the print service provider can blame the customer for problems caused by faulty customer transparency flattening all he wants, the fact is that at the end of the day, the customer will not be satisfied, the print service provider will need to fix things and reprint at no extra charge, and what could have been a profitable job ends up resulting in a loss!

                    Under the new workflows, the customer provides PDF at the highest level of abstraction. RGB images are left as-is with their ICC profiles. Transparency is left "live." The print service provider then has two choices:

                    (1) If they have a reasonably-recent vintage PDF workflow system that has been properly maintained (software updates applied) over the years using either Adobe PostScript 3 or the Adobe PDF Print Engine technology, then these color-managed PDF files with live transparency should simply work!

                    (2) If they have ancient RIP software that at least conforms to the PostScript language level 2 specification, the print service provider can always successfully "print" such color-managed PDF files with live transparency to such RIPs via Adobe Acrobat 8 Professional. Such "printing" requires the print service provider to understand how to use Acrobat, but then again, the print service provider is more likely to be able to do this successfully than would a creative professional customer.

                    We do have experience in this area. I have been giving talks on these topics for five years at Creo (now Kodak) user conferences. The audience (all printers with ink under their fingernails) was at first skeptical. The good news is that what I hear from attendees at my talks when we return the next year is that my advise vis-a-vis maintaining content at the highest level of abstraction (ICC profile tagged images in their original RGB color spaces and live transparency) does yield a more streamlined workflow for both them and their customers with correct results.

                    There are of course, ifs, ands, and buts to this. Obviously, GIGO (Garbage In, Garbage Out) always applies. No matter what the print service provider does, if the creative professional customer abuses use of transparency, the results will reflect that. But that is true of everything. Furthermore, these workflows don't work if the print service provider has a wonderfully up-to-date workflow system (such as Prinergy 4) but plugs in a popular OPI system that under-the-covers converts all PDF to PostScript language level 1 via an ancient version of GhostScript (throwing away all transparency operators and color profiling), does its "thing," and the converts the resultant PostScript back to PDF via the same ancient version of GhostScript! We call this type of workflow PDF Interruptus! (By the way, I did not make up this example.)

                    • 7. Re: What is PDF/x-4?
                      Level 1
                      Thank you for this real goog explanation!
                      • 8. Re: What is PDF/x-4?
                        Thanks for all the info.
                        If I'm sending pdf's to China, where they probably aren't up to date with everything, should I just stick with pdf/x1A:2001, acrobat 5 compatible for now?

                        We were using custom pdf settings in our art department before sending to printing vendors.... but sometimes I would get fine white lines in the pdf's and started using pdf/x1a:2001 and it seems ok now.

                        I still have a LOT to learn about pdf creation. Maybe there is an Idiots guide?
                        • 9. Re: What is PDF/x-4?

                          If your printer doesn't know what they are doing, or your files are going to an Asia Pacific country (where they are using far older equipment for print than the US), the safest format for you to predict file problems and transparency flattening issues is PDF/x-1a. Also, check the file in Acrobat with Overprint Preview on then with it off. Often the spot colors or objects that are dropping out are there, but Overprint must be enabled on your output device for them to print.

                          Dov is right on all counts (and a wonderful explanation), but if your print shop doesn't understand transparency flattening or doesn't have a device with the new PDF Print Engine, you are safer sending pre-flattened files. However; Adobe doesn't recommend this workflow.

                          Check here for PDF guides for printers & designers:


                          scroll down to find printing guides on the left.

                          Kelly McCathran
                          • 10. Re: What is PDF/x-4?
                            Dov Isaacs Adobe Employee
                            Make no assumptions either way about printers in Asia Pacific countries! The stereotype of such printers using archaic hand-me-down RIPs, presses, and workflows is totally inappropriate today. In many cases, they are leapfrogging into the future with the latest and greatest on all fronts. In fact, smug print service providers with Luddite attitudes in North America and Europe who cling to old workflows with outdated RIP and workflow software ("if it ain't broke, don't fix it") are no longer having to worry about competition with Far East printers solely due to price, but also on quality and reliability.

                            That having been said, never assume anything about what your printer can or cannot accept or better, reliably print from what you provide. Discuss it first and agree before send anything!

                            - Dov
                            • 11. Re: What is PDF/x-4?
                              Hi Dov-

                              I have a couple questions for you.

                              1. I am curious Has PDF/X-4 has attained its ISO specification/certification?

                              2. Our department is currently in an XINET FULLPRESS environment and our Mac Operators are experiencing a host of transparency issues that point to XINET'S use of Ghostscript.

                              Our brand standards require use of transparency across all marketing channels and our current work around is to export PDF's directly out of InDesign using the PDF 1Xa (2001) designation and have run in to some issues as a result. Drop shadows rendering at a lower resolution ect. I also have concerns about the vector to raster trap issues that accompany this sort of flattening. (Is this still a justified fear, or do most RIPs now accommodate Transparency flattening?)

                              It would seem that the 4x standard would resolve these issues however I am concerned that our vendors may not be able to handle the 4xa PDFs in their respective workflows.

                              Any thoughts?

                              Scott Kwiat
                              • 12. Re: What is PDF/x-4?
                                Level 1
                                PDF/X-4 was sent to publication by the committee many months ago, but has yet to be actually published by ISO. It is, however, a complete and final standard and many vendors have implemented against it including Adobe and others.

                                Ghostscript doesn't support native PDF transparency. If you plan to use PDF/X-4 and native PDF transparency, you will need to find a replacement - perhaps one based on the Adobe PDF Print Engine.

                                PDF/X-1a doesn't support native transparency - it MUST be flattened as part of the creation process which may indeed yield the types of results that you are seeing. That's why X-4 was created - to avoid those issues. Any modern RIP will handle the transparency correctly.

                                • 13. Re: What is PDF/x-4?
                                  Dov Isaacs Adobe Employee
                                  Thanks Leonard for stepping in while I was asleep in India. :-)

                                  We hope that the official PDF/X-4 spec will be finally published by ISO within a few months. It was actually approved last spring and we thought that the ISO editors would get it out within a few months. Unfortunately, our editor has been interesting to deal with.

                                  With regards to Xinet, we believe, based upon information given to me by one of their reps, that their OPI functionality actually converts PDF to PostScript via GhostScript throwing out all transparency and color management attributes, performs the OPI operation, then uses GhostScript again to convert the resultant PostScript back to PDF. If this isn't a formula for workflow disaster, I don't what is!

                                  Supposedly a newer version of their software doesn't suffer from "PDF Workflow Interruptus" but I certainly would be very cautious of any product from a company that displays such a blatant lack of understanding of PDF print publishing workflows.

                                  - Dov
                                  • 14. Re: What is PDF/x-4?
                                    Level 1
                                    Thanks Guys.
                                    • 15. Re: What is PDF/x-4?
                                      Laurens Leurs Level 1

                                      Meanwhile over a year has passed and PDF/X-4 still remains a somewhat obscure file format. It is quite logical that the adoption of a new standard takes time though.


                                      Those looking for an overview of PDF/X-4 might be interesting in my write-up at http://www.prepressure.com/pdf/basics/pdfx-4

                                      • 16. Re: What is PDF/x-4?
                                        Dov Isaacs Adobe Employee
                                        Hardly a somewhat obscure file format. It is the recommended PDF/X format for PDF print publishing workflows using Adobe Creative Suite products.
                                        Little print companies like Quebecor are in the process of rolling out full support for PDF/X-4 having successfully used it with small companies like Hearst.
                                        PDF/X-4 is the basis for the new VDP printing standard, PDF/VT which is about to enter the approval vote process.
                                                  - Dov
                                        • 17. Re: What is PDF/x-4?
                                          Laurens Leurs Level 1



                                          I don't doubt that PDF/X-4 will be important and frequently used in the long run. But as you point out yourself, companies are only now starting to look into it. GWG's next standard will be based it. PDF/VT isn't finalised yet. Even when these standards are released, there will still be a bit of lag before the industry picks this up: vendors have to make software that can handle the standards, customers have to purchase these systems, trials have to be run,...


                                          I think that at this point in time PDF/X-4 is still obscure.

                                          • 18. Re: What is PDF/x-4?
                                            Dov Isaacs Adobe Employee

                                            I did not say that companies are only now beginning to look at it (PDF/X-4). Those are your words!


                                            When the printer and publication companies I mentioned are in production with PDF/X-4, that is not beginning to look.


                                            In this case, I will humbly suggest that obscurity is more a matter of your frame of mind with regards to this standard than reality. Those in print production who continue to be in denial of reliable 21st century print workflows will be the ones who become obscure, otherewise known as "out of business!"


                                                      - Dov

                                            • 19. Re: What is PDF/x-4?
                                              Laurens Leurs Level 1

                                              Whether 'rolling out' equals 'looking into' or 'in actual use' is a question of semantics and one's view of marketing speak  :-)


                                              I'll let Google tell us how much interest there is in PDF/X-4. If it is 'that hot', many people must be looking for information about it. According to the Google Adwords tools, the monthly global search volume on the (exact) keyword 'pdf/x-4' is 480. 'pdf/x-3' scores the same. For 'pdf/x-1a' it is 880 and for 'pdf/x' it is 3600. 'pdf' scores 1830000.


                                              We both agree that PDF/X-4 is the way to go. That is more important or interesting than the question whether it is happening now or 'real soon now'.