The black art of PDF
Filed in Books & greetings cards - July 15, 2009Just to recap: I want to create a book using Blurb. Blurb accept PDF uploads and specify that they require PDF/X-3 (an experimental fighter plane). My preferred page layout programme (Apple’s Pages) exports to PDF.
But not, sadly, to PDF/X-3.
However, the operating system does allow “printing” to PDF/X. For reasons that are unclear, Apple isn’t very forthcoming about what this is, does, or how it can be configured.
PDF-X is a subset of PDF that’s used in the printing industry and contains the minimum information needed to print the document.
The broad consensus around the net, though, is that this “printing” process is X-3 compliant. Specifically, PDF/X-3:2002 compliant. I’m presuming (hoping…) that this means that there is an Apple technical document kicking around that I haven’t stumbled across.
The Wikipedia page about PDF types is not very clear, but this page on thegraphicmac.com is (create better pdfs by understanding the formats).
PDF/X-3 is basically the same as PDF/X-1a except that it allows RGB data in the files.
And:
PDF/X-1a – This is the absolute best way to send a PDF for output, in my opinion. It is the standard used by the vast majority of the printing industry.
So, the theory is that a Mac user should be able to produce a book layout in any application and then use the operating system to “print” to PDF/X-3.
This is quite difficult to test. A websearch shows numerous products for, and discussions about, testing whether a PDF is compliant to the specification. It matters if you are receiving PDFs from the world for printing (and the products are geared for that sort of user and assume that you have the professional version of Acrobat etc.)
All I’ve been able to do is to check that the file isn’t being unduly compressed. In fact using the operating system to produce a PDF/X file creates a file that is marginally bigger than using the application to produce a PDF file on the “best” setting.
Without a PDF expert to hand that is about as far as I’m going to be able to take my understanding. Cover me, I’m going in….
(My thanks to the many people who commented or emailed with information or help about this subject.)
I feel a download of the ISO standards coming on…
July 15, 2009 @ 12:14 pm
My understanding in regards to Apple’s PDF-X conversion process is that it is in fact PDF/X-3 compliant, but the quality of the conversion is not the best. Color management is missing and the resolution is not so great.
Some browsing pulled up this link:
http://www.icalamus.net/tutorials/howto_create_pdfx.php?lan=en
If you haven’t seen it already.
Cheers,
Dalton
July 15, 2009 @ 2:14 pm
I’ve gone off and read the standards. Explanation in this post.
dalton, if Apple’s PDF/X conversion process is missing the colour management then it is not compliant with the standard.
July 15, 2009 @ 4:24 pm
Dalton/Martin – and therein lies the problem for this average joe.
There are some known problems:
http://pagesfaq.blogspot.com/2009/01/pdfx-problems-in-leopard.html
but the whole colour management thing seems to go around in circles. Some people say yay and some people say nay.
July 15, 2009 @ 4:35 pm
Colin, for PDF/X, the standards (ISO 15930 series) are quite clear: colour management is required – item profile and output intent. Any file that doesn’t have it, doesn’t comply.
July 15, 2009 @ 5:12 pm
Martin – that much I understand. What I’ve never seen is any statement from Apple as to what that print function actually does and whether it is standards compliant. All the people on the net who claim it is are doing so by assertion. As are the people who claim it isn’t.
July 15, 2009 @ 5:48 pm
Why am I doing this, I don’t even use Mac??
So I’ve read through the references, programming guides, links from the other comments etc…
This is what Mac OS X (10.4 and up) does for PDF/X and colour management:
the print engine does the PDF/X conversion, flattening etc as per Dalton’s link. If the file is complicated, has links etc (i.e. non PDF/X compliant) it chokes. As it should.
When a PDF/X is created it calls on ColorSync for the profile data required, putting it in the right place for the PDF/X format.
It’s a 2-step process.
What Dalton’s link does is just that colourspace bit, without the proper conversion of the PDF file. That’s why they’re getting problems. If the original file wouldn’t convert to PDF/X in normal print mode, ColorSync does nothing about it, all it does is colour space management.
PDF/X printing in OS X inherently embeds colour profiles as per the standard via ColorSync (I know, I checked the programming reference and API guides).
So it seems a bit of care in creating the document is required, then the print management should take care of the rest for you.
I need to get out more.
July 15, 2009 @ 9:01 pm
Why am I doing this, I don’t even use Mac??
For beer the next time you come this way…
Interestingly, although I’ve created a PDF/X file from my SoFoBoMo 08 file, I can’t create one from the 09 file. Given that the 09 file is the 08 one with the pictures replaced, it doesn’t leave me filled with confidence. The only immediately observable difference is that the 08 file contains images in flattened grayscale, whereas the 09 file has RGB images.
I also can’t print to PDF/X from a single image in Preview either.
I think that I’ve got to back off and learn a *whole* lot more about this.
July 15, 2009 @ 9:54 pm
Fare thee well. In case you should disappear down the PDF well, know that reading your blog has been a pleasure. If you succeed and reemerge in the light of day, please report back so that future generations may profit from your experience.
July 18, 2009 @ 10:05 pm