Hugh McGuire recently asked a good question on Twitter: Can you include a PDF in an EPUB? On the Pressbooks blog, he discussed some of the answers he received and some possible solutions. Apparently, it’s technically possible to treat a PDF as an image in an EPUB. Who knew?
Why would I do that? It’s a question that, quite reasonably, came up as part of the Twitter discussion. Why on Earth would you put a PDF in an EPUB? Shouldn’t that content be made into flowable HTML like everything else in the book? There are more effective ways, for example, of presenting tables in EPUB, which is one possible use of a PDF. Could there really be a good reason for this?
In fact, a project here at UNC Press made me wish I could embed a PDF, and for similar projects in the future I might try it. (Assuming, of course, such a thing would work on a diverse number of e-reading devices. If it doesn’t, then no dice.) We put together an enhanced ebook for a recently published biography of civil rights leader Septima Clark. The book, Freedom’s Teacher by Katherine Mellen Charron, is currently available on certain Kindle and Nook apps and devices, and will soon be available through Google, as well.
We approached the project as a way of opening up the archives and making them accessible to the reader. Thus, most of the enhancements are audio clips from oral histories used by the author during her research. They are embedded within the text and supplement the main argument, much like illustrations do. We also included transcripts and annotations in an appendix, as well as links to the archives themselves. Along with the audio clips, the book has a number of new photographs and documents, including letters written by Clark and her associates.
As you can see in this example, we included the first page of a letter or document in the main text, with a link to the appendix where you can view every page of the letter in more detail.
In the appendix, we made each page of the letter an image which filled the size of the page. A reader can obviously zoom in closer if they want, or they can flip through to the next page and see the rest of the letter.
Most of these letters were only a few pages long, and so simply placing a couple of large images back-to-back with forced page breaks in between isn’t a big deal. However, in a couple of cases we had documents that were 10 to 20 pages long. It would have been much more convenient and easier to simply bundle these together as a PDF, whether as part of the spine or simply as an “attachment” within the zip file that the reader can open and browse.
Obviously, the enhancements of this book are exactly that: all of the information and analysis central to the main argument and narrative is in the original, non-enhanced version. These letters and documents give you additional information. Our idea, while working on it, was to create a model for publishing the kind of open-access, networked scholarship increasingly central to academic work. Even though this book had nearly 100 enhancements, it’s the tip of the iceberg for the sorts of things we may be able to do in the future, as an historian’s research becomes more deeply and integrally embedded within her published work.
Anyway, there’s one example where including a PDF within an EPUB would be useful. Treating the documents as images worked perfectly fine, but the ability to provide a large chunk of supplementary data within the main EPUB has, I believe, clear uses in future scholarly work.