PDF/X-6 ISO norm for digital print
With the publication of PDF 2.0 in 2017 (first revision in 2020), new parts of the standard were also made available. These concern the formats PDF/A, PDF/VT, PDF/R and PDF/X. They were improved and adapted. Since PDF 2020, PDF/X-6 is now recommended as the successor to PDF/X-4 for professional printing. PDF/X-5 was based on PDF 1.6 and additionally allowed multi-channel ICC profiles, but this version has not been very popular so far.
PDF/X – Standard data format for the printing industry
The PDF/X format was introduced as the first ISO standard for PDF and was developed exclusively for the printing industry. X stands for Exchange. PDF/X unites all the properties that are important for print templates as PDF files. Above all, it is a matter of enabling a true-to-sample transmission of data from the pre-press stage.
The PDF format as a data container can transport more than is needed for the pre-press stage. However, PDF files should contain all the information intended for print production. Thus, the first version of PDF/X was created in 1995 to enable this data exchange. This format was then developed further and further, so that in 2001 the ISO standard PDF/X-1a was introduced, as well as in 2002 and 2003 the ISO standards PDF/X-2 and PDF/X-3. This was then considered the standard data format for the printing industry. With PDF/X-4, a standard was then created that met the demand for an exchange that was as media-neutral as possible. The current standard since 2020 is PDF/X-6.
All about the current PDF/X-6: ISO 15930-9:2020
A special feature of PDF/X-4 was that it allowed the use of the same colour spaces as PDF/X-3, but in addition it was possible to work with transparencies and layers. In printing, PDF/X-4 is often used for textiles. PDF/X-6 has now been developed as a successor version with some improvements for digital print templates and should always be used when you have to meet today’s print requirements. Especially with logos, it is extremely important that an ideal reproduction of spot colours is possible. PDF/X-6 brings new possibilities in terms of colour handling and offers functions such as page-based output intents, black point compensation and spectral measurement data for spot colours (CxF). PDF/X-6 also uses the PDF 2.0 function of page-based output intent.
An overview of the most important innovations with PDF/X-6:
- Depth compensation (ISO 18619:2015) at document level/ parameters for depth compensation (PDF/X-6 stipulates that depth compensation must be activated in the absence of an explicit specification).
- Separate output condition
- DPart metadata (With PDF/VT (Variable Data Printing and Transactional Printing), DPart metadata was developed and is now also included in PDF 2.0. The metadata enables applications that go beyond variable data printing.
- Spot colour information with CxF/X-4/ Spectral data information for spot colours on XML basis of CxF/X-4 (ISO 17972-4)
- Mixing Hints/ Interaction of spot colours in printing (print sequence, opacity of spot colours)
- Notes and graphic annotations possible
- Form fields and digital signatures possible
A distinction is currently made between the conformance levels PDF/X-6 (completely blind data exchange) and two further sub-versions for special applications:
- PDF/X-6p: applies to documents with an external ICC profile as output condition (successor of PDF/X-4p based on PDF 1.6)
- PDF/X-6n: external output condition for N-channel profiles, use of multicolour profiles (successor of PDF/X-5n based on PDF 1.6)
The previous PDF/X version and PDF standards remain valid, of course.
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