Why Not Just Use PDF?


I assessed two competing digital paper products in the early '90s: Adobe Carousel (later renamed Acrobat) and Envoy. I settled on Acrobat, based on Adobe's deep expertise in print via PostScript. The idea of a timeless, reliable digital file format remains appealing today, especially when that format is ubiquitous, easy to create, search, and use (not to mention an ISO standard). Creating a PDF file from a properly styled word processing document, such as Microsoft Word, OpenOffice, or WordPerfect, gives you both print fidelity and automatic hyperlinking. You can be sure of a rendition faithful to the print version. Moreover, users on Windows, Mac, and UNIX platforms will see and use it the same way.

So if you are working on corporate marketing materials such as white papers, why not just create PDF files for electronic distribution? That is not a bad strategy, but increasingly it is looking like an incomplete strategy. Two things require rethinking that strategy: proliferation of various reader platforms, each with its own screen dimensions, and a new publishing standard. Granted, most of these platforms can accept and display PDF files, but it is increasingly awkward to view PDF files, a one-size-fits-all format, on small screens.

Can you ignore those smaller screens? Look how popular the Kindle and iPad are, as well as various other tablets, netbooks, and smartphones. Moreover, according to a July report by the Pew Internet & American Life Project, 35% of Americans own a smartphone, and 25% of smartphone owners use that phone for most of their web browsing.

If you want the greatest number of eyeballs, you must consider two increasingly used ebook formats: MOBI (Amazon's proprietary Kindle format) and EPUB. EPUB is a vendor-neutral standard developed and managed by the International Digital Publishing Forum (IDPF). In May, EPUB 3 became a proposed specification, with a final version expected in the second half of 2011. MOBI has proven its wide acceptance via the Kindle and Kindle readers. However, if you prefer an open standard to avoid vendor lock-in, EPUB is your choice.

So what can EPUB 3, the next EPUB release, get you that PDF cannot? The standard says that EPUB 3 aligns with HTML5 and adds support for increasingly important features such as interactivity, vertical writing, global language capabilities, MathML, and improved accessibility. EPUB 3 does this largely through styling and layout enhancements, separating content from form. The list of vendors supporting EPUB 3 is large and includes Adobe Systems and Google.

To get some vendor insights into the emerging standard, I contacted Devorah Bloom of Data Conversion Laboratory, Inc. (DCL) and Smashwords, Inc.'s CEO Mark Coker. DCL is a long-time provider of conversion and publishing services, with deep roots in SGML and XML. Smashwords is a publishing services firm founded in 2008. It has provided simple ebook publishing and marketing services to more than 22,000 authors and publishers. I asked each why anyone should change from creating PDF via styled word processing files. Both are quick to assert that PDF is a fine print-oriented format. PDF has established itself as a format you can count on in the long-term.

A major EPUB 3 advantage, according to DCL, is that EPUB (like MOBI) allows reflowing text to avoid all the horizontal or columnar scrolling you must do with PDF, especially on small screens. EPUB supports multimedia (something PDF also does) and the XML standard MathML, which is useful for documents needing to express math equations. Bloom says that native support within publishing systems for EPUB is growing, and there are many converters from PDF or Word to EPUB. However, converters are blunt instruments that often produce less-than-desirable results. Coker agrees that reflowable text provides rich accessibility experiences: change font sizes, line spacing, font color, and the like for a customized reading experience. If you use Smashwords' style guide, you can output to PDF, EPUB, MOBI, HTML, and even plain text (the ultimate in accessibility). Smashwords converts and distributes documents for free, with a sales commission of 10% on sale prices. Since you are unlikely to sell corporate marketing materials, you may initially want the services of a full-service conversion vendor such as DCL.

In the meantime, PDF will continue to serve you well for traditionally sized screens, but you may want to begin evaluating EPUB or MOBI for their delivery advantages. How you actually write for delivery to different screen dimensions and readers, however, is a larger question than any ebook specification.