Custom Printing Options for Creating and Proofing PDFs

We are inundated with PDFs today. Almost every application you own can create a Portable Document Format file, from OpenOffice to Microsoft Word to Adobe Acrobat. But if you are a graphic designer, how do you know that the PDF you are creating for your commercial printer is appropriate for the target offset or digital printing technology? How do you know your job won’t go horribly wrong?

What Is PDF/X, and How Does It Differ from PDF?

Those PDF files you can distill from standard office applications can include a multitude of options (including such features as hyperlinks or dynamic forms) that don’t pertain to custom printing. In the case of digital and offset printing, you actually need fewer rather than more features. You need to limit your options to ensure accurate results.

Enter PDF/X. PDF/X is a subset of standard PDF that addresses such graphics exchange issues as “output intent” (the conditions for the final custom printing device), color management, definition of the printable area including trim and bleed specifications, and “active content” issues (essentially the exclusion of rich media such as audio and video, and interactive features such as comments and forms).

Here are some of the options explained one at a time. A book could be written about this information, so consider this just a starting point for discussion with your commercial printer.

1. Printing Conditions: This includes color and ink data targets, one of which might be “CGATS TR 001 SWOP,” which refers to a specific collection of “Specifications for Web Offset Publications” (SWOP). These standards addresses such custom printing issues as color separation, screen angles, total area coverage of ink, undercolor removal, gray component replacement, color and ink data targets, and proofing processes, to name just a few. In short, these variables address how your final job will look and with what technology it will be printed.
2. Color Management: This specification focuses on the color space of the print job, including whether it is CMYK and whether it includes spot color information. Data on the ICC profiles (i.e., the color profiles for the custom printing job) can be addressed as well, along with any information on calibrated (color managed) RGB elements (in most cases, of course, your offset job will be CMYK and/or a spot color rather than RGB).
3. Definition of the Printable Area: This specification includes information on the “Media Box, Trim Box, Art Box, and Bleed Box.” All of these pertain to the job size and format and whether and how the ink will bleed off the page.
4. Active Content: PDF/X will omit the following from your print-ready files: embedded audio and video, signatures, interactive forms and comments, and other PDF features that are appropriate for the exchange of inter-office documents or forms but that don’t pertain to offset and digital custom printing.

Flavors of PDF/X

To complicate matters within this technical arena, PDF/X comes in many varieties (including PDF/X-1a, PDF/X-3, PDF/X-4, and PDF/X-5g. Most of the variables used in determining which of these sub-specifications to use involve:

1. whether the transfer from the designer to the commercial printer is “blind,” (i.e., requires no intervention by the printer)
2. the extent of the acceptable color information (CMYK plus spot colors, vs. other color spaces)
3. issues such as transparency
4. issues such as whether the PDF can reference graphics outside the PDF (usually, the PDF includes all fonts and graphics, but some of the alternative PDF/X formats allow printer replacement of graphics).

Ask Your Commercial Printer for Help

In most cases, you will probably only distill PDF files for print as PDF/X-1a compliant. You will probably also limit the color space in your job to only CMYK plus spot color. And you will probably embed all fonts.

It is essential that you discuss the various PDF options (PDF/X-1a, PDF/X-3, and such) with your commercial printer to make sure you set up your PDF document correctly. Different printers use different PDF workflows for various kinds of work (offset printing vs. digital printing vs. packaging printing). Finding a trusted and knowledgeable prepress operator within your custom printing vendor’s shop can save you stress and disappointment. In addition, your commercial printer can preflight your files to ensure that they are PDF/X compliant.

Reviewing a PDF Proof

Many people ask me what the difference is between the PDF they submit to their printer and the PDF proof they see if they request only a screen proof (virtual proof).

The difference between your PDF and the proof is that the proof has passed through the printer’s RIP (raster image processor) and has been converted from the curves and arcs of PostScript into a bitmapped format understandable by the platesetter.

To ensure accuracy, when you review a PDF proof from your commercial printer, you will need to check any logos you have placed in the file as well as any special type characters (such as the trademark symbol ™ and copyright symbol). You will also need to confirm that there was no reflow of copy (i.e., none of the type has moved from column to column or from page to page).

Beyond this list of things to check, your job should be fine as long as you have correctly embedded all fonts in the distilled PDF file. (Basically, any problems introduced between the submission of your PDF file and your receipt of the commercial printer‘s PDF proof should be confined to these areas.)

This entry was posted on Sunday, March 11th, 2012 at 6:05 pm and is filed under InDesign Software, Prepress, Proofing. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.