flight to their Acrobat Professional Suites. Several other software companies, such as Enfocus ( www.enfocus.com
),
Markzware ( www.markzware.com
), and Callas ( www.callas.de
) also offer PDF preflight software packages. A small investment in preflight software will save you time, aggravation, and probably thousands of dollars later on.
Confused about preflight and all the settings? You are not alone. For that reason, the Ghent workgroup, an international group of experts, has taken on the initiative to identify and create PDF profiles for the various advertising and commercial markets. To find out more about them, visit their web site at www.gwg.org
.
What is a PDF/X file?
PDF/X stands for Portable Document Format/eXchange. It is an accredited ISO standard for standardizing how PDF files must be created for print. It is a subset of one of Adobe’s PDF specifications. Each time Adobe releases a new version of Acrobat, a new PDF specification is also released (needed for the new features and enhancements). There is always a delay between the current release of and the latest version of Acrobat. It takes time to draft, discuss, and have standards approved. Quad/Graphics participates in the CGATS subcommittee that is responsible for creating and updating the PDF/X specification.
Think of PDF/X as a preflighted PDF file for print. The PDF/X specification is very specific about how a PDF file’s make-up must be to pass the PDF/X verification process. It mandates such things as all fonts must be embedded, all images must be embedded, what color spaces can be supported by that version of the PDF/X specification, output intents (specifies color model file was created for), and even includes support for trim/bleed boxes. It is also more generic in other areas because of the fact that various print markets have different requirements. For example, the image resolution for commercial and newspaper are on very different ends of the spectrum, so PDF does not specify a particular image resolution. This is where the Ghent Workgroup and others come into play. They have further defined the PDF/X standard to fit specific markets. The Ghent Workgroup refers to their rendition as PDF/X+ because they tailored the standard for certain market segments.
Typically you will encounter two different types of PDF/X files. They are PDF/X-1a and PDF/X-3. PDF/X-1a does not allow for color management (only CMYK images) and is the common format for North America. PDF/X-3 is a color managed workflow that can contain CMYK images as well as RGB and LAB. This format is widely used in Europe. To make it more confusing there are multiple versions of a PDF/X file. There is a PDF/X-1a:2001 and a PDF/X-1a:2003. The year signifies the year the standard was approved, but the difference is the version of the
PDF specification they are a subset of. The 2001 version is a subset of the 1.3 specification (Acrobat 4) and the 2003 version is a subset of the 1.4 specification (Acrobat 5). Refer to the chart as a reference for both PDF/X-1 and X-3.
PDF/X Version Reference ISO Version Reference Targeted Audience
PDF/X-1a:1999
PDF/X-1a:2001
PDF/X-1a:2003
PDF/X-3:2002
PDF/X-3:2003
PDF/X-4:2008
ISO 15930-1:1999
ISO 15930-1:2001
ISO 15930-1:2003
ISO 15930-3:2002
ISO 15930-3:2003
ISO 15930-7:2008
Complete exchange using CMYK and spot colors
Complete exchange using CMYK and spot colors
Complete exchange using CMYK and spot colors
Complete exchange using device-independent colors
Complete exchange using device-independent colors
Complete exchange using device-independent colors
Permits Color
Management of Data Subset of this PDF Specification
No
No
No
PDF 1.3 Specification (Acrobat 4)
PDF 1.3 Specification (Acrobat 4)
PDF 1.4 Specification (Acrobat 5)
Yes
Yes
Yes
PDF 1.3 Specification (Acrobat 4)
PDF 1.4 Specification (Acrobat 5)
PDF 1.4 Specification (Acrobat 5)
There have been numerous articles written about PDF/X file preparation and the Internet is a great resource of information on the subject. We encourage you to search the web for more information and the Ghent workgroup website ( www.gwg.org
) for more detailed information.
Quad/Graphics endorses the PDF standard 100% and we encourage its use.
How2PDF Guidelines – © Quad/Graphics, Inc., 2010. All rights reserved
Quad/Graphics, Inc. Technology Group
July 2010
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