When publishing a book, you may find yourself facing a dilemma – should I publish a paper edition only, or should I also have an e-book? And if I decide to go forward with both, what kind of format should I choose? How do e-books even work, and how do I make them comfortable to read on all kinds of devices?
Fear not – here’s the e-book 101 article you’re looking for! In the paragraphs below, you will find all the basic information you need – I will show you why e-books are worth the hassle and guide you through different formats and their pros and cons.
E-books 101: why you SHOULD have an e-book
First, let me share some statistics – it’s predicted that by 2027, over 1.1 BILLION readers will be reading e-books, and the market is set to generate $15.33 billion annually.
Between 2017 and 2023, ebooks borrowed from libraries and schools worldwide more than doubled from 155 million to 370 million.
- In the US, 20% of the population bought an ebook in 2023.
- In China, 27% of consumers bought an ebook in 2023.
- In Japan, around 19% of consumers bought an ebook in 2023.
- In the UK, around 17% of consumers bought an ebook in 2023.
- In Australia, around 13% of consumers bought an ebook in 2023. [i]
A lot of people read e-books for convenience or for accessibility – e-books can actually be more accessible to readers with sight impairments or reading difficulties than paper books. They weigh nothing – you can take 5 e-books on a trip, while taking 5 regular books significantly increases your amount of luggage. You don’t really need specialized hardware to open them – you can read on an e-reader, but also on your tablet, on your phone, or any other digital device.
The e-book market is growing, and is predicted to continue growing – giving your readers an alternative to a paper book is an investment that is very likely to pay off.
[i] All the statistics are from https://whop.com/blog/ebook-statistics.
E-book basics: EPUB, PDF, and other formats
There are two common e-book formats: EPUB and PDF.
EPUBs are, by far, the most popular – that’s the format that you will most likely receive after purchasing an e-book from Amazon or other large store. They come in two flavours – reflowable and fixed-layout, which I will go into more detail later. PDF is a format that you will probably see used in technical publications (manuals, textbooks, books with a lot of graphs and tables), some children’s books, and promotional e-books created by various online creators.
You might also encounter formats such as .kpf (which is the output format when exporting from Kindle Create – a program that can be used to prepare image-heavy publications for Kindle) or .azw (another Kindle format). Yet another one that you might be familiar with is .mobi – which was the main Kindle file type for years, but it’s been made obsolete by EPUB in the most recent period.
How to open and read e-books
Both EPUB and PDF files can be read on pretty much all digital devices (with the exception of fixed-layout EPUBs, which require specific software to be read correctly).
If you’re on a Mac or iPad, Apple iBooks will open everything you need.
If you’re on Android, you should be able to open EPUB and PDF files with any e-book reading app, such as Moon, ReadEra, Kitaboo, or the Kindle app.
If you’re on a PC, you will need a PDF-reader (such as Adobe Reader, Adobe Acrobat, Foxit PDF, etc.) for PDF files, and a separate program for EPUBs, for example Calibre (https://calibre-ebook.com) or Thorium (https://thorium.edrlab.org/en/).
Important!
The same EPUB file will look slightly differently in every app. The reason for that is because EPUB files are not regular text files, like a PDF or a Word or Pages file. Instead, they are made of code – xHTML, CSS, and XML – and every e-book application will interpret that code in its own way.
EPUB vs PDF
PDF files look pretty much the same as files with regular print books. They have the same build, the same layout, and can include any number of illustrations, tables, etc. – so if you need to have an e-book that precisely reflects the paper edition, this is your go-to format.
However, they do have certain downsides:
- They can end up being very large, especially if you have a lot of illustrations
- They are created in specific page sizes and don’t adjust automatically to your screen – so if you open a large PDF on a smaller screen, you will have to manually zoom in, read the text on the page, zoom out, go the next page, zoom in… which can be rather annoying if you’re reading a novel.
Reflowable EPUB files are accessible and adjustable. They don’t have actual “pages” – how much text you can see on the screen depends largely on the reader’s own settings. The reader can change the font, margins, line spacing, and text size – basically, anything they wish to. This makes for a much smoother, more comfortable reading experience that can be adjusted for each individual consumer.
EPUBs can also be interactive – have clickable hyperlinks, footnotes and endnotes, include videos and other media types. They also have accessibility features – they support text-to-speech, screen readers, and navigational aids for the visually impaired readers.
This file type is also preferred by most retailers – there are some (though few) that won’t accept and sell PDF files.
… but again, they’re not without downsides:
- They don’t work well with very complex styling, large amounts of images and tables. The most functional EPUB is a simple EPUB.
- They don’t support complex image layouts – so if you want to have things like text overlaid on an illustration in your e-book, this is not the right format.
- You have to be able to give up a degree of control – you won’t be able to keep the book looking the same on every device.
Fixed-layout EPUB files, in turn, work more similarly to PDF files – they also let you keep the layout from the printed version (which is why they’re often used for children’s books with complex layouts and a lot of illustrations). However, not all retailers sell them, and there is a limited range of devices and apps that will show them correctly – they work great on color Kindle and Kobo devices, as well as Apple iBooks and some select apps on Android. Personally, If I were to choose between a PDF and a fixed-layout EPUB, I’d choose PDF first. Fixed-layout would be my choice if the retailer doesn’t sell allow for PDF sales (for example: Amazon only allows PDFs in specific languages). [ii]
[ii] Check KDP’s file formats here: https://kdp.amazon.com/en_US/help/topic/G200634390
How EPUBs are made: let’s look under the hood
EPUB files are technically ZIP archives containing an XHTML file with the content, a CSS file with a stylesheet responsible for how the file looks, as well as images and other supporting files.
Personally, I usually create e-books for books that I’ve already formatted for print in Adobe Indesign – and my print workflow is already adjusted in such a way that the EPUB export will need as little manual coding as possible. Despite that, it usually takes a few hours of manual work and styling to make the e-book look decent and remove errors and superfluous code. The more images, tables, and other visual elements you have in the file the more time you will need to make the e-book presentable.
If you have Indesign file that someone unused to working with e-books formatted for print only – cleaning that up is usually an enormously time-consuming exercise in frustration, which is why I don’t accept such jobs often – and why it costs more when I do.
I won’t bore you with the technical details – it’s enough to say that most EPUBs are either created by the way of Indesign export and then manually corrected, or coded entirely by hand.
The manual corrections can be done in several ways – you can open and edit the code even in a program as simple as Notepad, but I usually use Sigil – a piece of software that lets you crack an EPUB file open.
In Sigil, I usually adjust the spacing, size of illustrations, remove superfluous code that makes the file unnecessarily big, and tweak the rest so that the book looks good on all the popular devices. An EPUB file also needs to pass a validation check before being submitted to any store – the script is the same everywhere and you can find free validators online, for example at https://draft2digital.com/ or https://www.epubvalidation.com.
That’s not the end, though – after everything is technically correct, you still need to test how the file actually looks on different e-readers. I always test the EPUBs I produce on Kindle, iPad, Kobo and Android, as well as several PC apps, to make sure I catch all the errors.
And after the file is triple-checked and validated, it’s ready to be uploaded – to any self-publishing platform or retailer of your choice.
That’s it!
I hope you found this article useful – let me know if you think it’s lacking something, or if you have an additional question.
I’m always up for a chat – get in touch via marta@martadec.eu.
