PDF/VT

The PDF/VT Standard

The PDF/VT standard has been published in 2010 as ISO 16612:2010. It is »designed to enable variable document printing (VDP) in a variety of environments«. (Note that the abbreviation VDP is sometimes expanded to »Variable Data Printing« as an alternative to »Variable Document Printing«). PDF/VT documents contain the final content elements and associated metadata, but not any variables or templates. The predecessor standard ISO 16612-1:2005 specified the PPML/VDX formats based on PDF 1.4. However, this older standard was missing several PDF features and relied on constructs external to PDF. The modern PDF/VT standard is based on PDF/X-4 and PDF/X-5 and supports PDF 1.6 features including transparency, layers, and ICC-based color management. In addition to the requirements of PDF/X the PDF/VT standard adds supplementary features to PDF to meet the requirements of high-volume personalized printing. PDF/VT enables high-performance rendering (ripping) of digital print files by adding efficient resource management to PDF.

Since PDF/X includes color management features and support for ICC color profiles, PDF/VT inherits the same features. While color management may present a learning curve for organizations which up to now restricted themselves to black and white printing, it opens up the arena for colorful print products with consistent color reproduction.

The scope of PDF/VT includes the important segments »variable document printing« and »transactional printing« which are defined below.

Variable data printing

Variable data printing (variable document printing, VDP) - also called personalized or one-to-one marketing - generates individualized pages, i.e. some or all printed pages are different. Variable content is taken from a database and used to customize each document. VDP is mainly used for marketing purposes since personalized documents catch the recipient’s attention much faster than unpersonalized mass mailings. Some examples:

  • Business correspondence with variable name and address information.
  • Customized brochures with variable text and graphics elements, where the variable elements are selected based on a set of composition rules. As a result, graphically rich and unique documents are created.
  • Truly personalized offerings where the actual contents vary based on the location, sex, age, purchasing history or other known information about the recipient.

Transactional printing

Transactional printing produces records of a purchase, account, or other transaction, such as bills, statements and policies. If promotional or marketing messages are included in the transactional document the combination is called transactional-promotional, or transpromo. Common industry-specific examples:

  • Financial services sector: a financial statement includes customized offers tailored to the individual recipient.
  • Utility sector: an electricity or gas bill contains customized service offerings based on the customer's actual consumption.
  • Telecommunications sector: a phone bill includes custom discount offers based on the specific type and number of phone connections the customer had in the previous month.

Conformance levels: PDF/VT-1, PDF/VT-2, and PDF/VT-2s

ISO 16612-2 specifies three PDF/VT conformance levels, all of which are based on PDF 1.6:

  • PDF/VT-1 is designed for single-file exchange and based on PDF/X-4. All resources required for rendering a PDF document are contained in a self-contained PDF/VT-1 file. For this reason PDF/X-4p with external output intents is not allowed.
  • PDF/VT-2 is designed for multi-file exchange and based on one of the standards PDF/X-4p, PDF/X-5g, or PDF/X-5pg. PDF/VT-2 documents can reference external output intents, external page contents, or both. A PDF/VT document and all its referenced PDF files and external output intents are collectively called a PDF/VT-2 file set.
  • PDF/VT-2s is designed for streamed delivery where document generation and rendering can be interleaved. A PDF/VT-2s stream is a MIME package containing one or more PDF/VT-1 files or PDF/VT-2 file sets (or both flavors) plus all referenced files.

Note that PDF/VT-2 and PDF/VT-2s can be considered dead since these standards are not widely implemented
in RIPs and other software.

PDF/VT-3

PDF/VT-3, to be defined in ISO 16612-3, is the successor of PDF/VT-1. It will be based on PDF/X-6 (any conformance level) and therefore PDF 2.0. At the core of PDF/VT there are rules for dealing with repeated contents and transparency. The respective requirements for encapsulated XObjects in PDF/VT-1 relate to the use of transparency on any page in the document (not only on the page where the XObject is used), which places a big burden on some types of software. In contrast, the PDF/VT-3 rules relate only to the use of transparency on the same page which greatly simplifies processing.

Multi-file exchange and stream delivery have been abandoned for lack of industry support; therefore no successors of PDF/VT-2 (which is based on PDF/X-4p, PDF/X-5g, or PDF/X-5pg) and PDF/VT-2s will be specified.

PDF/VCR-1

PDF/VCR-1, which has already been published in 2017 as ISO 16613-1, is a new standard aimed at Variable Content Replacement (VCR). It is targeted at high-volume production of personalized items such as credit cards, loyalty letters, individualized printing e.g. for pharmaceutical product packaging with lot number and expiry date, or serialized tickets.

A PDF/VCR-1 document is based on PDF/X-4 or a newer part of ISO 15930. Therefore, PDF/X-6 and PDF 2.0 can also be used as the base format for PDF/VCR.

In a sense, PDF/VCR offers what some people erroneously believed PDF/VT to deliver: while PDF/VT transports final contents, a PDF/VCR document constitutes a template with placeholders. The template is merged with variable data at ripping time, thus creating the final document. The placeholders are marked in the template with techniques taken from Tagged PDF with some custom extensions. The variable data, called a data sequence, is provided in the form of a CSV file per RFC 4180.

More Information

The PDFlib Whitepaper »A Technical introduction to PDF/VT« explains the technical concepts which are specified in PDF/VT on top of PDF/X-4 and PDF/X-5.

During our implementation of PDF/VT support in PDFlib we collected various notes on the ISO 16612-2:2010 document. These range from minor editorial changes to technical errors and a few suggestions. Interested parties can download our notes here. Note that you will need a copy of the original ISO standard in order to use this document.

PDFlib and PDF/VT

PDF/VT support in PDFlib, PDFlib+PDI and PDFlib Personalization Server (PPS) is based on PDF/X-4 and PDF/X-5 support which has been introduced in 2009. All relevant PDF/X features and requirements in PDFlib apply to PDF/VT as well. This includes color management features with ICC profiles, output intents for characterizing the intended printing condition, and rules regarding the use of color, layers, and transparency in the document. PDFlib supports the creation of documents which conform to PDF/VT-1 and PDF/A at the same time.

PDFlib features for creating PDF/VT-1 have been added with a focus on automatic creation of unique identifiers and a flexible API for describing document part hierarchy and Document Part Metadata (DPM). Since PDFlib doesn’t know anything about the relationship of multiple documents which have been created separately, scope hints and encapsulation hints can be provided by the application developer. Programming examples for creating PDF/VT are available in the PDFlib Cookbook.

Code and PDF Samples for PDF/VT

Our Cookbooks contain the following code samples for PDF/VT:

  • The starter_pdfvt1 sample in the PDFlib Cookbook creates a self-contained PDF/VT-1 document;
  • The dpart_to_xml sample in the pCOS Cookbook demonstrates how to read and extract Document Part Metadata (DPM) from a PDF/VT document and store it in the XML format specified in the PDF/VT standard.

PDF/VT Resources

ISO 16612-2:2010: Graphic technology - Variable data exchange - Part 2:
Using PDF/X-4 and PDF/X-5 (PDF/VT-1 and PDF/VT-2)
https://www.iso.org/standard/46428.html

PDF/VT Application Notes by the PDF Association
https://www.pdfa.org/publication/pdfvt-application-notes/

Cal Poly Graphic Communications PDF/VT Test File Suite
https://www.pdfa.org/resource/cal-poly-pdfvt-test-suite/

Do PDF/VT Right: How to make problem free PDF files for variable data printing
http://www.globalgraphics.com/doPDFVTright/

Adobe PDF Print Engine with support for PDF/VT
http://www.adobe.com/products/pdfprintengine/

PDF/VT Technical Working Group of the PDF association
https://www.pdfa.org/community/pdf-vt-technical-working-group/

International Cooperation for the Integration of Processes in Prepress, Press, and Postpress Organization (CIP4) is the organization responsible for the Job Definition Format (JDF):
http://www.cip4.org/

ICS - Common Metadata for Document Production Workflows
Metadata format recommended for use with PDF/VT
https://confluence.cip4.org/display/PUB/Common+Metadata+for+Document+Production+Workflow+ICS