AFP or PDF? Opinions differ on which data format is better for output management. Considering its “triumph” in electronic data exchange, the Portable Document Format (PDF) is often viewed as irreplaceable. To be sure, PDF from Adobe, originally designed for office communication, is establishing itself in more and more industries. Meanwhile numerous special versions have become ISO standards – such as in archiving (PDF/A), digital prepress (PDF/X) and engineering (PDF/E) – with others waiting in the wings. PDF is also increasingly popular as an exchange format in healthcare and variable transaction output. No surprise there – PDF has real benefits. Having emerged from the widely used PostScript page description language, it offers the best properties of vector graphics, which are better than in AFP. PDF also has many extra functions: direct access to pages, compression, and interactive navigation.
Without a doubt, one of the biggest advantages is integrated font management. All the fonts used can be directly embedded in the document, ensuring that the text will always look exactly the same when displayed. To save space, the fonts can be restricted to only those characters that are actually used.
Other unique features argue in favor of PDF. If a document needs updating, the changed objects are simply added at the end. This way, minor additions such as watermarks or text corrections are quick and easy to incorporate. Document creation is likewise uncomplicated. How the objects in the document are arranged is irrelevant when generating a PDF. No preliminary step to arrange the objects is needed; PDF needs only a single work step. It’s also possible to embed metadata (title, author, creation date, etc.). Metadata are important for any downstream processing of the document, such as archiving, but do not affect its final appearance. Furthermore the format supports various types of encryption, access controls and digital signatures, making it just right for processing confidential documents being sent over the Internet or used in a Web browser application. PDF is not just a pure document format, and hasn’t been for some time. Common technologies such as multimedia, XML, Java, form processing, etc. have become part of this format. Because it’s possible to include additional attributes such as the document structure, reading direction, and alternative explanatory text for images, PDF continues to rise in popularity. It is a valuable and high-power format that outperforms AFP when it comes to document display.
Nonetheless, AFP remains the most used format for mass printing. The reason is its compact data stream, which allows print speeds of up to 3,000 pages per minute. In addition, resource management is more flexible and comprehensive than for PDF. AFP deals more intelligently with paper tray control, for example. A control file can be used to specify which pages are output on which printers and how (simplex/duplex). It is also possible to set the AFP data stream for simultaneous web and single-sheet printing, an option that PDF does not have (yet).
Yet another advantage is that AFP remains the only data stream with integrated error handling. AFP printers automatically check whether all the characters and numbers from the data stream were actually printed. If something is missing or incomplete, it generates the appropriate error message. This control function is not only important for producing account statements and checks. It’s no accident that AFP sets to tone in industrial production of invoices and account statements. Almost all high-performance printing machines the world over are run using AFP. With prepress, it’s a different story. PDF has probably finally established itself here. Nonetheless, PDF will not be replacing AFP in the foreseeable future, nor does it have to. Why not bundle the advantages of both data streams to make output management of a company more efficient overall? Why not use the “coexistence of two strong formats” to create and output “intelligent documents” using all possible channels? While “data delivery” is handled more and more by PDF – high-value, secure and powerful – AFP strengths play out in the “last mile” to the printer.
Output management today is not about producing as many documents as possible as fast as possible. The trend is toward intelligence, to documents with content that is both generally and inclusively accessible. In this context, freedom from barriers is important. Inclusion is growing in importance from a legal standpoint as well. Someone with impaired sight has the same rights as a sighted individual to the content of the document. The PDF/UA format takes this into account. It uses a screen reader (see Glossary) to read a document with semantic and stylistic accuracy. Even though PDF/UA still has some way to go to create completely barrier-free documents, it does address important – and essential – requirements, such as the definition of the reading direction, language and document structure and the identification of artifacts.
Metadata – the alpha and the omega
Intelligent and efficient output management requires one thing above all: metadata that can be read and saved and can travel with the document throughout the entire generation and conversion process. Metadata are the foundation for downstream or parallel processing, such as when a document not only needs to be printed, but also output as an E-Postbrief. Metadata is already a must for archiving. However what sounds logical is still problematic in practical application. In many companies, the data are incomplete. PDF can help here because metadata can be integrated, displayed and read without difficulty in this format.
The potential of the PDF format is far from exhausted. The enthusiasm on the part of many suppliers of output management systems (OMSs) for developing new PDF standards clearly illustrates that more innovations in intelligent document processing can be expected. Among the companies behind this drive is Compart. This globally active OMS specialist contributes to numerous associations and organizations. Among its activities Compart participates in the PDF/A Competence Center, of which it is a founding member, and works to promote worldwide format standardization in the AFP Consortium. The company also stands energetically behind the establishment of new standards such as PDF/UA and PDF/VT. Compart’s DocBridge family of products support PDF standards as well as AFP, from both the input and output side.
With comprehensive expertise in data stream optimization, Compart is a key driver for development of innovative solutions that target efficient output management that lowers operating costs and reduces the sources of error in document generation, processing, conversion and output.
PDF: A multifaceted classic
Developed by Adobe Systems in 1994, the Portable Document Format (PDF) was and remains, by virtue of continuous advances, the worldwide standard for electronic data exchange. It was the first platform-independent exchange format for electronic documents and its many benefits put it front and center in nearly all market segments. Numerous special versions have emerged over the years that address the special requirements of specific industries and areas of application.
Overview of major versions:
PDF/X (PDF for Exchange): Was the first ISO standard for PDF and grew out of the very special requirements of the graphics and print industry. The standard was published in 2001 and regulates the transmission of print templates. It has been continually developed since then. In digital prepress, PDF/X is the most widely used format today.
- Contains all data for fonts, graphics and print-out in high resolution
- Fully embedded fonts
- Storage of color profiles – precise definition of color management
- Current release: PDF-X5.
PDF/A (PDF for Archive) for compact, long-term electronic archiving, an ISO standard since 2005. This standard was developed to meet the need to archive large numbers of documents with the ability to display them countless years later in the same quality as the day they were generated (with all the stored fonts, colors, logos, graphics, etc.) Many properties of PDF/A originated in PDF/X, such as correct embedding of fonts and colors.
- Font subsetting as a means of keeping the PDF file compact
- Embedding of digital signatures
- Exact definition and storage of color profiles
- Encryption and locking (password protection) are prohibited
- No context-dependent and dynamic functions that could change the content and layout (barcodes, audio/video data)
- PDF/A-1a: Guarantees that the text content is extractable and the logical structure of the document as well as the natural reading process of the integrated text material remains the same
- PDF/A-1b: Guarantees that text and other page content are clearly reproduced; however does not guarantee that either is understandable and readable
- PDF/A-2: Standard pending certification with new enhancements for merging several output files into one PDF/A container and Unicode capability.
PDF/E (PDF for Engineering): Standard format for technical documents from engineering, architecture and geoinformation. Adopted in 2008, this standard may eventually be integrated into PDF/A as a special version of the PDF archiving standard.
- Display and interactive processing of 3D graphics and models
- Exchange of plans, drawings and other construction documents.
PDF/VT for variable transaction output: This format allows incorporating variable data into the PDF, guaranteeing a secure end-to-end process. The international standard, published by ISO in August 2010, has many advantages over previous formats for printing variable data, especially maximum interoperability. In PDF/VT, the well-known assets of PDF are combined with several special PDF/X functions and are now available for the world of personalized printing. This includes long-term archiving, since PDF/VT can be seamlessly converted into PDF/A format.
PDF/VT was developed because more and more companies are delivering their printed files in PDF format, which is not as practical as AFP for large volumes of output (see Glossary 2). The development of PDF/VT also advances the convergence of offset print files and variable digital data printing. Experts assume that the PDF/VT and AFP will initially enjoy equal status on the market.
PDF/UA (Universal Accessibility) to create and display documents that are also accessible to users with impaired sight or motor skills. The objective of the yet-to-be-established ISO standard is to define how PDF documents and the information elements they contain (graphics, text, multimedia, form fields) must be made accessible to this segment of the population (freedom from barriers).
- Defines the sequence and language in which the text must be read
- Takes into account/ignores delimiters
- Tagging principle: what text passages and blocks belong together? What should not be read (e.g., page numbers, headers/footers, comments, source citations)?
- Storage of document structure, reading direction, and pronunciation.
PDF/H (PDF for Healthcare). This format was developed with the support of the Committee on Healthcare Informatics of the American Society for Testing and Materials (ASTM). It is designed for the standardized exchange of patient data in healthcare. The idea underlying the format was to create an electronic “container” using the advantages and functions of PDF for archiving and data exchange between all the participants: clinics, hospitals, patients, private physicians, and insurance companies.
PDF/H can save the following data:
- Clinical reports
- Laboratory reports
- Image data
- X-ray and CT images
- ECG and EEG data.
Its platform-independence and sophisticated functions for embedding various types of resources and data make PDF an excellent format for long-term storage and display of important medical data that is true to the original.