Authoring EPUB from InDesign CS3

Several of our key developers, including our lead architect Peter Sorotokin, recently started a new Adobe Digital Editions blog . One of the first posts delves into best practices for authoring EPUB XML from InDesign CS3. The team plans to cover a wide variety of topics relating to the technical underpinnings of Digital Editions and various authoring workflows. Future posts I’m looking forward to include automatic conversion of DocBook XML to EPUB, and delving into the use of XSL-FO master page templates as an EPUB extension that facilitates dynamic, adaptive layout. If you have topics you’d like to see covered, suggest it in a comment on Peter’s intro post.
There’s a broader issue with use of our new InDesign feature that I’d like to touch on here: the tradeoffs between authoring PDF and EPUB. Many content authors have long been firmly rooted in a “WYSIWYG” mindset, and some have as a result expected EPUB to be some kind of XML version of PDF, that preserves all the composition of InDesign. That’s not the case: if you want final-form fidelity, you should stick with PDF – that’s what it was designed for, and it does its job very well. EPUB is designed to represent a more adaptive portable document – one that encapsulates a sequence of linear text flows (“Stories” in InDesign/InCopy lingo). Content-level styling can be applied (via CSS), final-form content can be embedded within a text flow (as SVG or Flash SWF), and hints as to page-level formatting can be applied (via our XSL-FO-based extensions to EPUB), but at the end of the day it’s up to an EPUB processor to determine the proper page layout based on a user’s screen size, resolution, font size preferences, etc. And different EPUB renderers are free to make different line layout decisions.
One implication of this is that “your mileage may vary” in creating EPUB from InDesign CS3. If you have a nice linear book, with InDesign stories flowed into well-designed page templates things should go well – especially if you follow the tips in Peter & Piotr’s post. If you created page layouts manually in a “pasteboard” manner, then things may get a bit stickier. Again, you may choose in this case to just stick with high-fidelity PDF. Our DIgital Editions software natively supports both PDF and EPUB as first-class citizens. But if you want the benefits of adaptive layout, mobile device optimization, and increased accessiblity of using EPUB, you may wish to reconsider your authoring workflow, to more consistently utilize InDesign Story flows to pave the way for structured EPUB XML export. This is something else I hope the team will blog about in more detail down the road.