PDF/X

A: [Please note that the following answer has been shamelessly stolen from the PDF/X FAQ which can be found at http://www.ddap.org/solutions/pdf-x_faqs.html]

Michael Still (mikal@stillhq.com) [A172]

A: "PDF/X" can be thought of as a shorthand way of specifying most of what you need to tell somebody in order for them to create a file that's likely to print correctly when they send it to you, even if they don't understand the details of what it's doing for them. That's looking ahead a little to a point where applications include a 'PDF/X' check-box on their PDF export dialogs, but signs are that's not going to be too far off.

Phrased slightly differently, think of all file formats used for file transfers as being compromises between flexibility and reliability (where reliability is defined as the final printed piece looking like you expected it to).

At one end of the scale are application files like QuarkXPress documents. You can change those in whatever way you like if you have the application. Unfortunately the receiver of a file can also change them accidentally rather too easily, and the results you get when printing are dependent on many factors in the environment in which that copy of XPress is running.

At the other end of the scale you have copydot scans. Those will print absolutely as you expect, given the necessary provisos about resolution and calibration Ð that's part of why they are inflexible.

In between, in order of decreasing flexibility and increasing reliability, other options at other positions on the scale include PostScript, EPS, PDF, PDF/X and TIFF/IT. When I use a name like 'PostScript' in that list I mean the format in an otherwise unspecified way. It's always possible to push such a format towards the reliable end of the scale by using appropriate software to create it. In northern Europe many people use ProScript, which limits the options used in EPS files. A 'ProScript EPS' file might be placed on the scale somewhere between PDF and PDF/X. In the same way, appropriate use of pre-flight tools on PDF can give you a 'reliable PDF' much closer to where PDF/X is on that scale. The point of PDF/X is that it gives you a convenient and well specified label to use when asking for such a 'reliable PDF' file.

Martin Bailey (http://www.ddap.org/solutions/pdf-x_faqs.html) [A173]

A: The standard has been split into two. PDF/X-1 is a file format for what's known as "blind interchange", where all technical information and content is held within one single file and nothing needs to be supplied alongside it.

It's expected that publishers will make their specifications available to ad agencies and prepress houses. These will include page sizes, bleed allowances, number and types of hard copy proofs to be sent alongside digital files and file formats that will be accepted. No further technical discussion will be required in order to make a suitable PDF/X-1 file for delivery. Obviously commercial discussions are a separate matter.

PDF/X-2 will address exchanges where there is more discussion between the supplier and receiver of the file - the receiver may have certain fonts available which would therefore not need embedding, or maybe the receiver already holds high resolution images to replace FPOs (low resolution previews) in the supplied file.

Martin Bailey (http://www.ddap.org/solutions/pdf-x_faqs.html) [A174]