A nostalgic look back at the ISO PDF/X standard

In this blog post, Martin Bailey recalls his days as the first chair of the ISO PDF/X task force and how the standard has developed over the last 20 years.

Over the last few years there has been quite an outpouring of nostalgia around PDF. That was first for PDF itself, but at the end of 2021 we reached two decades since the first publication of an ISO PDF/X standard.

I’d been involved with PDF/X in its original home of CGATS (the Committee for Graphic Arts Technical Standards, the body accredited by ANSI to develop US national standards for printing) for several years before it moved to ISO. And then I became the first chair of the PDF/X task force in ISO. So I thought I’d add a few words to the pile, and those have now been published on the PDF Association’s web site at https://www.pdfa.org/the-route-to-pdf-x-and-where-we-are-now-a-personal-history/.

I realised while I was writing it that it really was a personal history for me. PDF/X was one of the first standards that I was involved in developing, back when the very idea of software standards was quite novel. Since then, supported and encouraged by Harlequin and Global Graphics Software, I’ve also worked on standards and chaired committees in CIP3, CIP4, Ecma, the Ghent Working Group, ISO and the PDF Association (I apologise if I’ve missed any off that list!).

It would be easy to assume that working on all of those standards meant that I knew a lot about what we were standardising from day one. But the reality is that I’ve learned a huge amount of what I know about print from being involved, and from talking to a lot of people.

Perhaps the most important lesson was that you can’t (or at least shouldn’t) only take into account your own use cases while writing a standard. Most of the time a standard that satisfies only a single company should just be proprietary working practice instead. It’s only valuable as a standard if it enables technologies, products and workflows in many different companies.

That sounds as if it should be obvious, but the second major lesson was something that has been very useful in environments outside of standards as well. An awful lot of people assume that everyone cares a lot about the things that they care about, and that everything else is unimportant. As an example, next time you’re at a trade show (assuming they ever come back in their historical form) take a look and see how many vendors claim to have product for “the whole workflow”. Trust me, for production printing, nobody has product for the whole workflow. Each one just means that they have product for the bits of the workflow that they think are important. The trouble is that you can’t actually print stuff effectively and profitably if all you have is those ‘important’ bits. To write a good standard you have to take off the blinkers and see beyond what your own products and workflows are doing. And in doing that I’ve found that it also teaches you more about what your own ‘important’ parts of the workflow need to do.

Along the way I’ve also met some wonderful people and made some good friends. Our conversations may have a tendency to dip in and out of print geek topics, but sometimes those are best covered over a beer or two!

About the author

Martin Bailey, CTO, Global Graphics Software

Martin Bailey, Distinguished Technologist, Global Graphics Software, is currently the primary UK expert to the ISO committees maintaining and developing PDF and PDF/VT and is the author of Full Speed Ahead: how to make variable data PDF files that won’t slow your digital press, a new guide offering advice to anyone with a stake in variable data printing including graphic designers, print buyers, composition developers and users.

Further reading

  1. Compliance, compatibility, and why some tools are more forgiving of bad PDFs
  2. What the difference between PDF/X-1a and PDF/X-4

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What’s the difference between PDF/X-1a and PDF/X-4?

PDFX-1 PDFX-4

Which PDF/X should I use?

Somebody asked me recently what the difference is between PDF/X-1a (first published in 2001) and PDF/X-4 (published in 2010). I thought this might also be interesting to a wider audience.

Both are ISO standards that deliberately restrict some aspects of what you can put into a PDF file in order to make them more reliable for delivery of jobs for professional print. But the two standards address different needs/desires:

PDF/X-1a content must all have been transformed into CMYK (optionally plus spots) already, so it puts all of the responsibility for correct separation and transparency handling onto the creation side. When it hits Harlequin, all the RIP can do is to lock in the correct overprint settings and (optionally) pre-flight the intended print output condition, as encapsulated in the output intent.

On the other hand, PDF/X-4 supports quite a few things that PDF/X-1a does not, including:

  • Device-independent color spaces
  • Live PDF transparency
  • Optional content (layers)

That moves a lot more of the responsibility downstream into the RIP, because it can carry unseparated colors and transparency.

Back when the earlier PDF/X standards were designed transparency handling was a bit inconsistent between RIPs, and color management was an inaccessible black art to many print service providers, which is why PDF/X-1a was popular with many printers. That’s not been the case for a decade now, so PDF/X-4 will work just fine.

In other words, the choice is more down to where the participants in the exchange want the responsibility to sit than to anything technical any more.

In addition, PDF/X-4 is much more easily transitioned between different presses, and even between completely different print technologies, such as moving a job from offset or flexo to a digital press. And it can also be used much more easily for digital delivery alongside using it for print. For many people that’s enough to push the balance firmly in favour of PDF/X-4.

For further reading about PDF documents and standards:

  1. Full Speed Ahead: How to make variable data PDF files that won’t slow your digital press
  2. PDF Processing Steps – the next evolution in handling technical marks
  3. Compliance, compatibility, and why some tools are more forgiving of bad pdfs

About the author

Martin Bailey, CTO, Global Graphics Software
Martin Bailey, CTO, Global Graphics Software

Martin Bailey is Global Graphics’ Chief Technology Officer. He’s currently the primary UK expert to the ISO committees maintaining and developing PDF and PDF/VT and is the author of Full Speed Ahead: how to make variable data PDF files that won’t slow your digital press, a new guide offering advice to anyone with  a stake in variable data printing including graphic designers, print buyers, composition developers and users.

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