The cost and scheduling benefits of adding PDF proofs to your production workflow.
For one thing, there are several "flavors" of PDF. In order to make the right kind of PDF file for each output purpose, the print community has set standards for creating "proper" PDF files. For the printing industry, there is a PDF-X family of standards, created through the Ghent PDF Workgroup (GWG) based in Ghent, Belgium. But since the print community uses a variety of workflows and output devices, several sets of standards have been created dependent on the output intention. The good news is that Adobe Acrobat Professional and several other PDF creation tools (though by no means all) have these standard settings built in, so the people creating the PDF file can choose precisely which standard is used. The bad news is that not everyone is familiar with which standard should be selected. In fact, as you read this, a new standard called PDFX-4 is in the process of being created; it will allow for the use of transparency in PDF among other things.
A few other challenges when it comes to PDF proofing:
* The proof is in the RIP: Not all RIP devices currently in the field are capable of RIP’ing native PDF files. This is probably true more in the wide-format and quick-print segments of the print industry than for general commercial or packaging printers. You need a PostScript level 3 RIP to output these files, and many of these RIPs actually convert the PDF back to PostScript to handle the processing. That’s not always the perfect solution. More recently, Adobe has released the PDF Print Engine and made it available to third-party RIP vendors. This engine processes PDF files natively and understands how to properly handle things like transparency. But the number of such RIPs currently in operation is relatively small.