Publishing Word of the Day: PDF (Portable Document Format)

17 Jan

PDF (Portable Document Format)

An open file format created and controlled by Adobe Systems, for representing two-dimensional documents in a device independent and resolution independent fixed-layout document format. Each PDF file encapsulates a complete description of a 2D document (and, with the advent of Acrobat 3D, embedded 3D documents) that includes the text, fonts, images, and 2D vector graphics that compose the document. PDF files do not encode information that is specific to the application software, hardware, or operating system used to create or view the document. This feature ensures that a valid PDF will render exactly the same regardless of its origin or destination (but depending on font availability when fonts are not encapsulated in the file).

(From Wikipedia.)

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When I was a kid my mom worked as a reporter for our small-town newspaper. This was in the early ‘70s and they still used hot lead to set the type for the paper each day. (Hot lead means, loosely defined, that molten lead is put into molds to create metal letters that will be later coated with ink to print on paper.) The basic theory behind this printing process was fundamentally unchanged since Gutenberg’s time. Then, in the mid-1970s phototypesetting became the next evolutionary step in commercial printing technology. Finally, toward the end of the last millennium, PDFs made the next big leap forward, allowing printers (and publishers) to begin moving away from offset printing toward digital printing.

As the above definition from Wikipedia says, PDFs essentially produce a “fixed” version of a document that can be emailed or uploaded to any computer where, when opened, will look exactly the same every time anywhere, as long as it is viewed using the Adobe Reader or Adobe Acrobat. Initially this may not seem like that big of a deal, but for anyone who has tried, for example, to email a MS Word document—even when saved as an RTF (rich text format) file—all kinds of crazy and unpredictable formatting errors and other problems can crop up. That’s not so terrible when a student is emailing a paper to you in a distance learning class, but when you’re paying thousands of dollars to print hundreds of copies of a book, you want to make sure that it looks the same way every time it is opened up by your printer.

In addition, because a PDF is an electronic—that is, digital—version of a document, that means you can print one copy of a book at a time on a digital printer instead of having to do a large offset press run. TSTC Waco Printing Production uses a Xerox DocuTech to print the interior pages of all our books, which we deliver as PDFs. Finally, the other inherent advantage to PDFs is that if you want to make changes, updates, corrections, additions, or deletions to your source text, you can make those changes, convert it to a PDF in just about no time flat and you’re ready to go to print almost immediately.

As time goes by Adobe is constantly adding new features to its PDFs. Now you can do text touchup and some graphics manipulation on the PDF itself. (That’s handy for a guy like me who rarely does actual page layout with Adobe InDesign but receives PDFs as the final output from graphics staff at the office and on occasion needs to make odds and ends of changes before sending files off to print.) It is possible to put external Web links into a PDF as well as internal bookmark links within the document, useful when creating a PDF e-book. You can imbed movie and sound files into PDFs as well. A good resource for learning all about what PDFs can do is a book we keep in the office, Adobe Acrobat 7 PDF Bible. Also, as I learned a while back, a good Web site for learning about all things PDF is Planet PDF. I have often wished that the TSTC Waco’s Advertising Design & Print Technology department—they provide all of our graphics interns—taught a class just about Adobe Acrobat and PDFs but I’m not sure that’s going to be possible any time soon.

There is one thing to remember: PDFs are not perfect. We regularly have formatting issues crop up, especially when the source file being converted has a lot of graphics linked within it. Also, for really big, complex files, it’s better to burn them to CD to deliver to the print shop instead of emailing as attachments. And, finally, while it’s possible to embed a PDF into a page layout program and then produce a new PDF, this is not a good idea if the embedded PDF has any text in it.

Still, despite these issues that can crop up, the ubiquitous nature of PDFs means that they are around to stay (until the Next Big Thing comes along). . . and the reasons for that are their overall dependability and general usefulness.

Mark

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