Have you ever wondered why Kellogg's has so many different versions of Cornflakes? There's Crunchy Nut, Crunchy Nut Nutty, plus the classic Cornflakes. And then there are all those Frosties variations, but we won't go there. The reason for all these exciting breakfast possibilities is that people want choice, and to have the cereal recipe that suits their needs.

So it is with PDF-X. Publishers and printers produce a massive range of different types of materials using all sorts of diverse methods. In the weirdly wondrous world beyond sign and display making, printers and publishers have worked with standards bodies to develop versions of PDF to suit the output needs of specific types of workflow and production goals. Through their efforts we have PDF-X/1, PDF-X/2, PDF-X/3, PDF-X/4 and PDF-X/5, all of which are different parts within ISO 15930 for the exchange of graphics data based on PDF. Not all of these parts are still breathing, but the ones that are could be relevant for sign and display work particularly where workflows are already automated.

PDF and Shredded Wheat cater for a general set of tastes,

but the graphic arts needs something better suited to a gourmand's

tastes and that something is PDF-X

PDF-X/1 allows complete data exchange using CMYK and spot colour data, with PDF-X/1 based on PDF version 1.3 and PDF-X/1a based on PDF version 1.4. PDF-X/2 was for partial exchange of data but pined away and never got published. PDF-X/3, based on PDF version 1.4, is for complete data exchange including calibrated RGB and CIELa*b* colours, so it's more suitable for colour-managed workflows. A more up-to-date option for a colour-managed workflow is PDF-X/4, based on PDF 1.6, which is the version that supports transparencies, so PDF-X/4 contains all data required for output without flattening. For partial exchange of printing data using PDF version 1.6, PDF-X/5 is the one for you. There are different iterations of PDF-X/5, but we'll leave that for another time.

For a sign and display producer all this PDF-X guff can seem quite tedious, but the whole point of the ISO 15930 series is to provide a simplified means of exchanging pre-press digital data contained in PDFs. The objective is flawless output processing, so that all the snazzy features of InDesign or Quark XPress are fully supported and properly processed in the RIP, so that they appear as the designers intended.

It might seem a bit of a faff getting to grips with the different PDFs but if one of them can improve processing efficiency in your workflow it will aid your productivity and profitability as well.