Understanding PDF Standards – PDF/X

The PDF format was improved greatly after the International Organization for Standardization (ISO) purchased it in 2008. As the name suggests, this acquisition also came with some PDF standards that were put in place by ISO for PDF documents created in the future.

Such standards ensure that PDF documents can be opened in all PDF software that also follows the standard. Furthermore, three standard-subsets for PDF were established. The last article had a look at PDF/A, today, we check out PDF/X. 

The PDF/X Standard

The purpose of this PDF standard is the exchange and sharing of PDF with primarily graphic content.

The PDF/X subset contains seven standards that all make it easier to share graphics for flyers, posters, business cards, shirt designs and more between the creator, client, printer, and publisher.

All the versions inside this PDF-exchange standard have to follow certain rules.

  • PDF/X-1a: fonts have to be embedded, images are in CMYK or spot colors, no transparency
  • PDF/X-3: also allows¬†calibrated RGB, CIELAB, ICC Profile

The first editions of these standards were based on PDF 1.3 but later updated and based on PDF 1.4.

  • PDF/X-4: added support for transparency
  • PDF/X-4p: support of external ICC profiles
  • PDF/X-5g: supports external graphics
  • PDF/X-5pg: supports external graphics and references to external ICC profiles
  • PDF/X-5n: supports external ICC profiles to include more color profiles than previous standards

These 5 versions of the PDF/X standard are all based on the PDF 1.6 standard.

Related article: All about the PDF 2.0 Standard

Is PDF/X better than a “normal” PDF?

If you are a graphic designer or created something for printing using PDF as your output format, why should you choose PDF/X over the other PDF formats?

The most striking reason is that it performs more reliable in print. Thanks to the set and standardized color profile, you have more control over how the print will come out. Thus, using this standard will eliminate errors or, at the very least, reduce the chance for them occurring.