eBooks and ePublishing Formats

photo of a table device

eBooks and ePublishing Formats

What’s an ebook?

Ebook is a bit of a catch-all phrase. When someone uses the term ‘ebooks’, they could be referring to any of a number of different file formats.

Essentially, an ebook is a file that can be read on an electronic device, like a desktop computer, laptop, tablet, a smartphone, or an e-reader like the Kindle® or Nook®.

Common file types that qualify as an ebook are:

  • ePub
  • PDF
  • Mobi
  • Fixed Layout epub
  • iBook

Each of these file types has a slightly different purpose and various advantages and limitations.


An epub file is essentially a website that has been packaged. Chapters are documents linked together from one main document or a number of files. A Table of Contents (TOC) helps the device navigate through the sections.

ePub files are widely used, especially for novels and other text-based books. It has something that not all the others formats have — the ability to ‘reflow’.

A reflowable epub file is responsive to the device. An epub file will shape-shift to fit nicely on a screen no matter what the size or resolution.

The user can often change the typeface to an option they prefer and can change type size to reduce or enlarge.


Limitations of epub

You cannot have bleed (graphics or colour that runs over the page). That’s because when you are working with a reflowable electronic document, there is no page. The page is the user’s screen which may be small or very large.

Complex layouts will create headaches as everything is pushed into one column.

No shapes are supported. You can get around this by converting the shape to a jpeg, which it will support.

Master page items are ignored, as are overlays, tabs, returns, and indents unless they are assigned as Styles.

It is crucial to apply styles both Paragraph and Character styles for your epub files. The styles are important for how the publication will flow. If you ignore styles and set the type with Bold, italics, indents and so on wherever you feel, it will force the ePub to include CSS code for all these ‘overrides’. This will ultimately create a bloated file.  Styles will keep it lean and clean.

You also need to apply a Table of Contents Style.

You cannot currently convert a Microsoft Word doc to ePub. You need a program like InDesign to create it. Mac’s Pages software can also create an epub file.


This is the dedicated format for Amazon and the Kindle Direct Publishing (KDP).

Amazon will convert your epub file to a .mobi when you upload it to KDP.

Fixed Layout ePub

This format is good when you want a more magazine-style look, or kids book, such as when you have a lot of graphics or your layout is more complex than straight text.

The Fixed layout ePub can be created to deliver something to your reader that looks much like the layout you have generated in your source program. If the position of images and text is important, it could be better to sacrifice reflowable text functionality and go for the fixed layout as you can better guarantee the user experience.

Having said that, because it isn’t reflowable, it could be harder to read if the user is on a small screen, as they have to manually zoom in.


Most people know PDF. It is everywhere and even Internet browsers often have their own PDF reading software. The problem is that not all PDFs are created equally. They are not reflowable and you cannot upload a PDF to sell to Amazon, Google, Apple or most ebook retailers. PDF is fantastic for a lot of things but e-publishing is not one of them.


This is Apple’s own proprietary epub format. The Apple iBooks application only sells .ibook.

By uploading an epub file to iBooks Author, the iBooks Author application will convert to a .ibook file for sale and distribution from there. The bad news is that it isn’t used anywhere except by Apple iBooks, and it can’t be used on your own website.

The .ibook file is reflowable when the device is held in landscape mode. When held in portrait, it becomes fixed layout epub.


That’s a  snapshot of a few of the various e-publishing file formats.