KB180115252: What is PDF+

Question

What is PDF and what is it to me?

Answer

Before we get deep down in what PDF+ is, let's first answer some other questions that will help us to better understand the purpose of PDF+

Packaging metadata

Goal of adding metadata to PDF is to close the gap between the PDF imaging model and packaging production requirements.

This is the Plus of PDF+.

What is PDF? 

 PDF is a page description language (PDL). Its purpose is to show how a document (i.e. page) looks like when reproduced on a device.

What is metadata?

According to Wikipedia metadata is data that provides information about other data.

Let's take a barcode for example, in essence it is nothing more than a collection of black rectangular objects. There is no other (meta)data in the PDF that describes that these objects together form a barcode with certain properties.

What is XMP?

XMP is the Extensible Metadata Platform, an ISO standard created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.

 Esko decided to use this to add data to the Normalized PDF, enabling Esko and Non - Esko systems to retrieve core property information about the assets in a fast and efficient manner without the need of fully reading or parsing the file.

It can contain information about PDF data, but it contains just as well other metadata found in the file.

Examples of packaging metadata

1. Ink properties

Ink order, ink type, ink opacity are supported in PDF version 2.0. Normalized PDF uses version 1.6 which does not support these properties, so we store them in the XMP.
 

2. Barcodes

Barcodes are an essential asset of the packaging production.
 

3. Text properties

Text layout parameters are not part of PDF. They are different in each graphic editor! The same text block formatted in Illustrator, Indesign, CorelDraw, etc. will not have the same text properties when exported to PDF. It is the application that determines how the text will be formatted on PDF level.
 

4. Linked content, external references, channel mapping

5. Screening information

Esko dot shapes and calibration for object based screening
 

6. CAD information

Normalized PDF (Esko packaging PDF 1st generation)

What is Normalization?

The goal

1. Eliminate workflow issues through simplification of the rich public format PDFs.
2. Maximizing reliability by eliminating ambiguity early in the workflow, and a dedicated single purpose optimisation.

What happens during normalisation?

• Distillation of Postscript^® based file formats into PDF
• Completion of graphics with metadata for packaging preproduction purposes
• Injection of XMP data to summarize file information for faster info access for third parties
• Removal of all non-print related objects
• Simplification of complex PDF constructs (e.g. removal of obsolete clips and groups)
• Conversion of all graphics into device color space (CMYK, DeviceN)
• Extraction of image data for sharing and retouch purposes
• and many more …
   

Why should we move to native PDF?

The requirements of today's digitalized worlds have changed, the same assets need to serve different purposes. We need to be able to do late stage color management, for example RGB to MCP just before print. The same content needs to be available for online cloud applications.

There is also a need for two way collaboration on packaging assets to maximize the efficiency. For example Enfocus Pitstop can auto fix issues on the packaging assets, or you can have self-contained PDF production assets stored in the cloud.

Last but not least, the current PDF specifications are catching up with today's packaging industry demands (e.g. Ink order in PDF 2.0).

PDF+ (Esko packaging PDF 2nd generation)

“Serving the needs of the conventional and digital packaging, labels and sign and display industry.”

PDF+ introduced by ArtPro+

So in short a PDF+ is a PDF with metadata embedded in the file. It is completely self-contained, this includes font information, high resolution images, ICC profiles, etc. It has no restriction on graphical content, so it maintains color spaces and there is no need for normalization.

PDF+ also means there is no dependency on the XMP. It no longer relies on it for correct rendering. What you see is what you get.

Can I use PDF+ today?

ArtPro+

• Native PDF files will be saved as PDF+ files.
• ArtPro files are converted to normalized PDF files when opening them with ArtPro+. Saving such a file will result in a normalized PDF. ArtPro+ does not write .ap files.
• When opening a normalized PDF, ArtPro+ basically behaves like PackEdge. It stays within the constraints and updates all meta data accordingly. The result is a valid normalized PDF.

Automation Engine

PDF+ files will be currently normalized. We are working on making Automation Engine PDF+ native.

Sheet and cylinder layout

• Automation Engine can normalize and process PDF+ files when creating layouts.
• Plato 16 and ArtPro 16 allow for step and repeat of PDF+ files without the need of importing or normalizing them.