Best Document Size for EPUB Export
I'm trying to develop my first e-pub. What should my document size be or does that even matter?
This is a great question because it seems like there should be... but the truth is that there isn't. The reason there isn't is important: You don't lay out an EPUB "ebook." Rather, you arrange its flow.
Remember how you keep avoiding HTML because it's so annoying? For example, it's a pain to position things properly on the page, it doesn't really support fonts very elegantly, it's annoying to have to deal with a bunch of different browsers (which maddeningly can't agree on how to display your HTML files)? Well, guess what? EPUB is HTML!
(Bwah-ha-ha-ha-ha... I feel as though I were talking about soylent green!)
That's right: There is no escape from it. EPUB is HTML. And not the good kind, not the modern kind of HTML that can do fonts and cool layouts and such that we're all getting used to in the 21st century. Not, currently EPUB is basically a hacked-together mess of HTML and very basic CSS that will look different on every epub reader and that simply cannot represent much of what you wish it could.
So, because EPUB is basically html/css, you're basically creating a very long stream or thread. You can specify page breaks at chapter headings, but just as you don't know how an HTML file will look in someone's browser (because perhaps they have their font display jacked up to show text really large), you won't really know where most of your document's page breaks will be.
I guess, in some ways, the "best document size" would be 18 feet tall by about 6 inches wide (5.4m x 15 cm)... just one huge, long story. The document size doesn't affect the EPUB output, but at least you'd have a visual reminder that EPUB is more about flow than layout.