VIGC (the Flemish Innovation Center for Graphic Communication -- try saying that three times fast!) has reported that it recently tested -- and (mostly) found wanting -- a range of PDF viewing tools for their ability to correctly display PDF/X files. For the uninitiated, the term "PDF/X" refers to a family of PDF-based standards for commercial printing workflows. The idea is that compliant files can always be reliably displayed and printed without some of the hiccups that can occur when PDFs contain funky, non-standard elements, or even plain old mistakes. With that in mind, compliance with PDF/X at both the creation and viewing/processing stages is pretty important. If you have spent lots of time and/or big bucks on design, photography, layout, etc., the last thing you want is to see your print ad show up somewhere with the wrong colors.
According to VIGC's Didier Haazen, "If you use an inappropriate PDF viewer, you can't be sure that what you see on your screen is the same as what will come out of the RIP, out of a digital press." It's not necessarily the printer's fault, either. Using a non-compliant viewer when fine-tuning your document is a bit like dressing in the dark: you might get it right, but you never really know how it's going to turn out.
With that in mind, let's talk testing. Using a set of "perfect" PDF/X files, VIGC tested more than 20 different tools, including headliners like Acrobat and Adobe Reader, popular alternatives such as Foxit's offerings and OS X's built-in Preview, along with a handful of iOS apps and online tools. Unfortunately, the results were disappointing: almost all of the tools failed to correctly display at least some elements important for printing, including transparency, overprint and colors.
The good news is that Adobe Reader and Acrobat both performed well. For those who complain about the relatively large download size of good old reliable (Adobe) Reader, Haazen points out that there's a rather good reason that it's bigger than its "leaner" competitors:
[T]he PDF Reference, which describes the structure and all possible properties of the PDF file format, is more than 1300 pages thick. If you only put a small part of that into your software, you will get "light" software, but it will not know certain -- though important for the printing industry -- functions in a PDF e.g. overprinting, and therefore won't show that. This was something that we clearly saw in our tests.
He's not alone in saying so, either. Appligent Document Solutions' CEO Duff Johnson has also gone on the record to point out that, in the case of PDF readers, bigger can mean better -- as long as the additional size brings equivalent functionality. For the moment at least, it seems that perhaps Adobe Reader is still the best option for print workflows, and I salute it in all of its hefty glory.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.