Tag Archives: pdf/vt

Getting to know PDF 2.0: not only but also!

Are you ready for PDF 2.0? Register now for the PDF 2.0 interoperability workshops in the UK and USA.

In the middle of 2017 ISO 32000-2 will be published, defining PDF 2.0.  It’s eight years since there’s been a revision to the standard. We’ve already covered the main changes affecting print in previous blog posts and here Martin Bailey, the primary UK expert to the ISO committee developing PDF 2.0, gives a roundup of a few other changes to expect.

Security
The encryption algorithms included in previous versions of PDF have fallen behind current best practices in security, so PDF adds AES-256-bit and states that all passwords used for AES-256 encryption must be encoded in Unicode.
A PDF 1.7 reader will almost certainly error and refuse to process any PDF files using the new AES-256 encryption.
Note that Adobe’s ExtensionLevel 3 to ISO 32000-1 defines a different AES-256 encryption algorithm, as used in Acrobat 9 (R=5). That implementation is now regarded as dangerously insecure and Adobe has deprecated it completely, to the extent that use of it is forbidden in PDF 2.0.
Deprecation and what this means in PDF!
PDF 2.0 has deprecated a number of implementation details and features that were defined in previous versions. In this context ‘deprecation’ means that tools writing PDF 2.0 are recommended not to include those features in a file; and that tools reading PDF 2.0 files are recommended to ignore those features if they find them.
Global Graphics has taken the deliberate decision not to ignore relevant deprecated items in PDF files that are submitted and happen to be identified as PDF 2.0. This is because it is quite likely that some files will be created using an older version of PDF and using those features. If those files are then pre-processed in some way before submitting to Harlequin (e.g. to impose or trap the files) the pre-processor may well tag them as now being PDF 2.0. It would not be appropriate in such cases to ignore anything in the PDF file simply because it is now tagged as PDF 2.0.
We expect most other PDF readers to take the same course, at least for the next few years.
And the rest…
PDF 2.0 header: It’s only a small thing, but a PDF reader must be prepared to encounter a value of 2.0 in the file header and as the value of the Version key in the Catalog.
PDF 1.7 readers will probably vary significantly in their handling of files marked as PDF 2.0. Some may error, others may warn that a future version of that product is required, while others may simply ignore the version completely.
Harlequin 11 reports “PDF Warning: Unexpected PDF version – 2.0” and then continues to process the job. Obviously that warning will disappear when we ship a new version that fully supports PDF 2.0.
UFT-8 text strings: Previous versions of PDF allowed certain strings in the file to be encoded in PDFDocEncoding or in 16-bit Unicode. PDF 2.0 adds support for UTF-8. Many PDF 1.7 readers may not recognise the UTF-8 string as UTF-8 and will therefore treat it as using PDFDocEncoding, resulting in those strings being treated as what looks like a random sequence of mainly accented characters.
Print scaling: PDF 1.6 added a viewer preferences key that allowed a PDF file to specify the preferred scaling for use when printing it. This was primarily in support of engineering drawings. PDF 2.0 adds the ability to say that the nominated scaling should be enforced.
Document parts: The PDF/VT standard defines a structure of Document parts (common called DPart) that can be used to associate hierarchical metadata with ranges of pages within the document. In PDF/VT the purpose is to enable embedding of data to guide the application of different processing to each page range.
PDF 2.0 has added the Document parts structure into baseline PDF, although no associated semantics or required processing for that data have been defined.
It is anticipated that the new ISO standard on workflow control (ISO 21812, expected to be published around the end of 2017) will make use of the DPart structure, as will the next version of PDF/VT. The specification in PDF 2.0 is largely meaningless until such time as products are written to work with those new standards.

 

The background
The last few years have been pretty stable for PDF; PDF 1.7 was published in 2006, and the first ISO PDF standard (ISO 32000-1), published in 2008, was very similar to PDF 1.7. In the same way, PDF/X‑4 and PDF/X‑5, the most recent PDF/X standards, were both published in 2010, six years ago.
In the middle of 2017 ISO 32000-2 will be published, defining PDF 2.0. Much of the new work in this version is related to tagging for content re-use and accessibility, but there are also several areas that affect print production. Among them are some changes to the rendering of PDF transparency, ways to include additional data about spot colors and about how color management should be applied.

Martin Bailey, CTO, Global Graphics Software

Why online print is set to change

Remember in olden times how you sent a file to print on a wing and a prayer? OK, it wasn’t that bad!  But it was unreliable. Figures showed that print-ready file delivery had failure rates of between 30 – 70% and this was a real problem for print service providers with high throughput like magazine houses.

Then PDF/X came along and greatly improved the situation. It was strengthened by additional standardisation efforts from several other bodies including Ghent PDF Workgroup and Altona.

PDF/X worked because it ensured delivery of files ready to high-quality print. And because it dealt with the headache so well, print service providers recommended it.

Fast forward for a moment to today and to the tidal wave that is variable data printing. Most buyers deliver the brief and the dataset to the print service provider (PSP). A full service PSP will offer data mining, graphic design, composition and print. Offering a full service promises higher margins. If you only provide a print service you can expect lower margins, but your model connects better to web-to-print services that are burgeoning. But if you try to “just print” VDP jobs, those that fail will eliminate profit.

I’ve been invited to speak at the Online Print Symposium in Munich (17th – 18th March) about why PDF/VT and Industry 4.0 are set to change online print forever. The truth is that VDP has been hanging around street corners looking for a PDF/X. Well, now it’s found one because that’s what PDF/VT is. It’s been created to deal with every page being different and to give PSPs more control over the workflow.

I would go so far to suggest that print-ready file delivery of graphically rich variable data from outside the print company is unlikely to succeed without it!  And on that bombshell…!

To receive a copy of my presentation email me. Meanwhile take a look at http://www.globalgraphics.com/doPDFVTright

Martin Bailey, CTO, Global Graphics Software

PDF/VT – bringing all the advantages of PDF workflow to the world of variable data printing

Standards for variable data printing (VDP) have come a long way since the first work by CGATS to develop a universal delivery format in the late 1990s. In 2010 the International Standards Organization published the PDF/VT standard, marking the first really effective specification for a reliable, vendor-neutral exchange of variable data jobs, both within and between companies.

A special type of the PDF file format, PDF/VT is specifically used for variable data and transactional printing in a variety of environments, from desktop printing to high volume digital production presses. Built on PDF/X, it therefore brings all the advantages of that standard in enforcing best practices for reproducible and predictable color and appearance to the variable data and transactional print worlds.

The industry is gradually realizing its value to improve quality, competitiveness and productivity, and I’ve been working with the PDF/VT Competence Center, especially with Christoph Oeters (Sofha), Paul Jones (Teclyn bv) and Tim Donahue (technical consultant) to produce a new set of Application Notes highlighting the benefits of using PDF/VT and the workflows that it enables.

The Application Notes explain how to make the highest quality and most efficient PDF/VT files to achieve the required visual appearance of a job, so if you develop software to read and write PDF/VT files, for example in composition tools, RIPs, digital front ends and imposition tools, or if you work on print workflow integration, you’ll find the notes really beneficial. They also show how document part metadata can be applied and leveraged for VDP specific production workflows.

Of course, there are wider benefits to using PDF/VT: The adoption of PDF/VT will allow the industry to finally move towards a reliable, vendor-neutral exchange of variable data jobs, simplifying the process of variable data printing significantly.

The application notes are free to download, pick up your copy here: http://www.pdfa.org/publication/pdfvt-application-notes/.

Let me know what you think of them – feedback is always welcome.

Additional reading:
Do PDF/VT right

Do PDF/VT right by Global Graphics Software

 

PDF/VT for personalized print by the PDF/A Competence Center

Read the press release from the PDF Association (http://www.pdfa.org/2016/01/pdf-association-publishes-pdfvt-application-notes-showcasing-the-benefits-for-variable-data-print-streams/)

Free webinars on “Do PDF/VT Right”

For those who missed it at PODi and XPlor, I’m presenting two free webinars this week on “Do PDF/VT Right: how to make problem free files for variable data printing”, hosted by Dscoop University – the Digital Solutions Cooperative. You don’t have to be a member of Dscoop, nor an HP Indigo user to join.

If you’d like to sign up to hear me talk through the guide, download the “Top 5 tips” poster, and have the chance to ask any questions, please register using the following links:

EMEA: Tuesday, October 21, 1pm – 2pm CET: http://dscoop.org/p/cm/ld/fid=971

North America: Thursday, October 23, 11:00 a.m – 12:00 p.m. CST: http://dscoop.org/p/cm/ld/fid=967

The guide itself is, of course, still available at http://www.globalgraphics.com/doPDFVTright/

#dopdfvtright