Why another format of PDF?

PDF/X is a focused subset of PDF designed specifically for reliable prepress data interchange. It’s an application standard, as well as a file format standard. In other words, it defines how applications creating and reading PDF/X files should behave.

What’s the aim?

In short - process control.

The aim for creative is to provide a file that they can be confident will be printed predictably and correctly by the service provider, regardless of output.

The aim for service providers is to receive robust digital content files that they can be confident will run through prepress without requiring rework or causing errors and will allow them to meet (or exceed) customer expectations on press.

Bad files, errors in prepress, unprintable data and untrustworthy proofs lead to human intervention, which in turn increases costs, errors and delay*

The immediately measurable goals are:

• To improve matches proof to proof, proof to press, and press to press.
• To reduce processing errors in proofing and prepress.
• To reduce the complexity and cost of customer education.

Primary Advantages of PDF/x.

simplest 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.

 In polar opposition we ask for native files like InDesign documents. You have absolute control over change, however the receiver of a file can also change them accidentally rather than too easily.

Why PDF/X-3

While some market sectors require exchanges with all color data already converted to CMYK, others are better served by transferring data in other spaces, such as CIELab or RGB with a profile attached.

Pre-conversion to CMYK works best where there is a clearly defined CMYK color space to convert into. Remember that a set of CMYK values do not specify a particular color until you also define what device it’s being printed on – the same CMYK values printed on gravure, flexo, or offset litho presses, or on a laser or ink jet printer are likely to look quite different.

The same PDF/X3 file may contain data in color-managed color spaces (such as Lab, CalRGB or using an embedded ICC profile), and other data in grayscale, CMYK and spot colors. The combination means that images can be included in a defined RGB space (for instance), while solid black text can be guaranteed to print in solid black without unexpected color fringing caused by color management spreading the black data to all the process separations.

The primary difference between PDF/X-3 and earlier PDF/x subsets is that a file can also contain color managed data. PDF/x-4 is too new for many to supply in. The first PDF/X-3 standard, better referred to as PDF/X-3:2002 is published as ISO standard 15930-3:2002.

* automation is not possible without this kind of version control.