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Open Educational Resources

A guide for the location and/or creation of open educational resources.

Fixed Versus Reflowable Formats

The first decision to make is whether to use a fixed or reflowable format. How your eBook is presented to your readers is referred to as layout. Here, there are two options, fixed and reflowable. In a fixed-layout format, what your reader sees remains the same no matter what screen/device the reader is using. In a reflowable format, the content reflows to best fit the screen and is more readily adjustable by the user on their specific device. This format is easy to update and upload to all the major publishing retailers. The reflowable format works best for text-based eBooks and is readable on most e-Book devices. Reflowable format file types include EPUB, MOBI, HTML, and KPF.

Publications containing large amounts graphics, tables, and charts, may not come across as intended by the author in the reflowable format. In these cases, a fixed format may be preferable. With a fixed format the author retains more artistic control. However, the page contents may slide off the screen or font size could become too small if resized. This format reduces the reader’s ability for adjustments. Fixed formats include KF8 (aka AZW3), EPUB3, and PDF. Not every publishing retailer accepts the PDF format. A summary of the pros and cons for each is
given in the table below.

Reflowable (Standard Format) Fixed-Layout Format

Advantages:

  • Works with most devices
  • Readers control the display of text
  • Smaller file sizes
  • Cheaper to produce and update

Advantages:

  • Total control over text display
  • Can use graphics and design elements heavily
  • Multi-column pages available
  • Supports most fonts (device dependent)

Disadvantages

  • Simple, one-column pages only
  • No control over text display
  • Can use only specific fonts
  • No heavy design or graphic elements

Disadvantages

  • Smaller number of retailers and devices
  • Readability problems might occur
  • Large file sizes
  • More expensive to produce and update

(Source: Reflowable vs. fixed layout ebooks: Choosing the best format for your ebook.)

Considering the wide range of devices students may use, the ability to publish in EPUB and PDF appears to be a minimum requirement. EPUB is the most widely accepted eBook format. It is the standard format used by eBook publishers including Apple, Kobo, Barnes & Noble, and others. The EPUB is compatible with most e-readers, tablets, and smartphones. It has a reflowable format which allows text to adjust to fit the screen size. EPUB files can be easily copied and shared.

The ability to also provide content in HTML and DOCX is also highly desirable. KPF is a file format specific to Amazon and compatible with all Kindle devices. The PDF format is compatible with many devices but uses a fixed layout. PDF format is convenient for print-on-demand needs. Files can be password protected.

It appears that MOBI is no longer being supported (as of as of July 2021). KPF or EPUB should be used for reflowable books when publishing through Amazon. It seems that the MOBI format is still accepted for fixed-layout eBooks.

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