The Ebook Doctor — Part Three – Anatomy of an Ebook

When you know what an Ebook and E-reader really are, and how they work together, you can learn how to create files that will work properly for your customer/reader.

This post is split into two Sections. The first covers the principles and some useful tools for examining Ebooks. In the in the second Section we will take a detailed look inside the Ebook file.

In later posts we will get to the decision point on the format to use, the problems commonly found in Ebooks, and how to avoid them. And finally a step-by-step guide on how to get a good result.

Inside the Ebook?

Looking at the Anatomy of an Ebook will give you a feel for the overall structure of an Ebook and will give you a better perspective on why formatting your manuscript in very specific ways will help your file pass the import tests for Amazon, and other big book retailers — and make it readable on a much wider range of devices.


Simply put, the Ebook is a ‘packaged’ website, and an E-reader is a hand-held web browser.

The Ebook contains a series of connected web pages which can be displayed using a browser. The pages are stored inside a “Package” or “Container” file: MOBI/AZW (Kindle) or EPUB being the most common.


Although there are many Ebook formats out there, in practical terms there are only three that you need to think about when deciding on the format for your Ebook. These are EPUB, MOBI and PDF.

If your book contains mainly narrative text, and has only a small amount of formatting, then EPUB and MOBI are the most important formats for you. If you are producing a non-fiction book which has a more complex structure then a PDF files may be a better option for presenting the book.

MOBI is the core structure used by Amazon for their Kindle Ebook files. And, since Amazon is probably the biggest bookseller in the world, we all think of creating a MOBI/Kindle compatible file first. In reality, most professional designers will create an EPUB file first and then, when that file is ‘clean’, and passes all tests, it is converted into a MOBI file before uploading to Amazon. This makes the open EPUB structure the most important to look at in detail.

I will come back to the PDF format later, as a special case, because there are some difficulties when marketing PDFs through Amazon.


The EPUB package is really a ZIP file and if you change its extension “.epub” to “.zip”, the EPUB file becomes a true ZIP file which can be unZipped so that you can look inside and edit the files directly.

If you work on a MAC you can rename to “.sit” and you can extract in the usual way.

Unfortunately, you cannot just Zip the files again and change the extension back to .epub to re-create the EPUB file. Some of the files in the EPUB package cannot be compressed and you need some special ‘Tools’ to make the new file properly.

If you need to extract and re-compress EPUB files one great utility which does this is called eCanCrusher, from This is FREE to download and use and is a simple application designed to convert an EPUB folder into a compressed .epub file or vice versa. It needs no installation. To convert, you just drag/drop an EPUB folder or an .epub file onto the eCanCrusher application icon.

There is a version for both Windows and MAC at this link:


An Amazon MOBI files is a more complicated beast because there may be multiple formats inside the same ‘Package’. Amazon’s compilers will add the original source file, usually an EPUB, to the database. If you have worked with both EPUB and MOBI files you may have noticed that a Kindle book can be quite large compared to the EPUB file of the same book.

Cracking open a Kindle file is more complex than working with an EPUB but if you need to do so you can use KindleUnpack (formerly MobiUnpack) to unpack and inspect the contents of DRM-free Kindle Books or MOBI files. You can then modify the content as needed and rebuild the original with Kindlegen.

The program is Open Source and you can get it here…

And you can get more info here…

…but beware, disassembling and re-assembling a Kindle file may not get you back to an acceptable file. Also, if files contain DRM (Digital Rights Management) you will not be able to open them in the same way. You can find out more about the MOBI structure here…

As an aside – surveys of sales of files with and without DRM show very clearly that files WITHOUT DRM sell much better. The complexity of managing files with DRM is off-putting and many customers avoid them for this reason.

We will come back to the details of editing inside an Ebook package later but at this point it is best to just note that it is really better to get the structure and formatting set up correctly inside your Word Processor so you don’t have to crack open the final package later.

Testing the converted files is another very important step and if we go through a couple of cycles of “Convert file – Test – Correct original –Convert again – Test again” until we get the right result there should be no need to crack open the Ebook file. More on this later too.

Converting from Word Processor to Ebook

The purpose of the Ebook format is to display the book content so that it looks like pages in a traditional printed book. When we create the book content on a Word Processor, the file that is saved is not always in a format that can be displayed in a web browser (Depends on your word processor) so it needs to be converted into the language used to create web pages ‑ HTML / XML / XHTML.

When you convert a Word Processor file into an Ebook the conversion translates the text into individual XHTML files for each chapter, or section, and puts together a list of those files and a set of instructions to the E-reader to tell it the order in which to display the pages.

We also need to tell the E-reader the formatting to use when the text is displayed. Websites use ‘Cascading Style Sheets’ (CSS) to describe the way the type should look on the screen — the font, the position of text on the screen and whether it is bold or italic, the spacing before and after paragraphs, etc. CSS also controls the position of graphic elements like photos and illustrations. All the formatting that you impose on your book text has to be translated to CSS file if it is to look the way you want it to, so you need to take a lot of care to make sure that the way you format your manuscript inside your Word Processor is easy to translate accurately to CSS.

The important point here is not that you have to learn how to write HTML or to create a CSS file, but to know that if you format your original text in specific ways the conversion process will work seamlessly and your final Ebook will look like you want it to, and will pass the acceptance tests of the Ebook retailers.


The Epub standards have been around for a long time and most of the devices in the market are designed to use the EPUB Version 2 standard, first published in 2007. However a new standard has been available since 2011, EPUB Version 3. V3 is quite sophisticated and can use fonts in a different way from the earlier versions but most Ebooks are still produced using Version 2 because of the vast number of older E-readers still in the market that only support V2 and do not support all the functions built into V3.

In the next instalment we take a more detailed look inside the Ebook.

©DavidCronin 2015

Other posts in the series.


The Ebook Doctor – Making your own Ebooks by David Cronin – Part One.

Over the coming weeks David Cronin will be giving a step by step guide to formatting your Ebook for both Mobi and Epub.  Although Moyhill is a Self-publishing company we are also aware that many authors wish to do the entire process themselves and we have always been very happy to assist those with that level of commitment.  Our philosophy is that the better all Ebooks look and read the more credibility Indie publishing will achieve.  It benefits our own authors if the reading public and critics have a healthy respect for self-published books.

Part One.

Now that we can see vigorous growth in the Ebook market even more of us ‘closet writers’ are going to come out and publish our own books without the ‘help’ of either Mainstream publishers or Self-publishing support services. With so many new books hitting the market it is even more important today to make each book stand out from the crowd.

We can be forgiven for believing that all we have to do to create an Ebook is to write the text and then click a few keys and ‘Hey Presto’ we have an Ebook for sale on Amazon.

In the most literal sense this is true. But will the Ebook look good, and will it ever sell? The answer is YES, but you need to take a step back and take a little time to learn a bit about how your Word Processor and Ebook conversion software can help you turn your manuscript into a good looking Ebook that will sell.

It’s a bit like cooking a meal. If you have all the right, perfect, ingredients you can produce a meal worthy of a Michelin Star ‑ or a hash. When you use the software tools to create an Ebook it is the equivalent of taking all the ingredients, in an un-prepared state, and boiling them in a big pot for an hour or so. If soup was your intent then maybe you might get lucky and get something edible… but is this a reasonable way to treat your carefully selected ingredients – your Manuscript?

The message that you will hear me repeat very often is about Quality. You need to step back for a moment and read the recipe, or even a few ‘cookery books’, before sending your ‘Dish’ out into the world for critique.

How long did you spend writing your book, carefully crafting and re-crafting sentences, characters and book structure? A little more time spent on the final presentation is well worthwhile if you are going to make an impact.

IN this short series of articles I will show you the steps that you need to take to make your Ebook look good and pass through the “gateways” of the big Ebook retailers.

The Cover and the ‘Blurb’ ‑ The psychology of selling a book

In print publishing, it is the Cover that always makes the first impact on the prospective customer, then the ‘Blurb’ that appears on the back cover of the book. The importance of both the Cover and the Blurb have not changed in the Ebook world. These are still your most important marketing tools.

Traditionally, publishers estimated that you had a maximum of about 3 seconds for the cover to attract the customer. If the cover did not make any impact then no sale would take place. If the cover raised the customer’s interest then he/she would turn the book over and read the Blurb. If that was interesting then the customer might flick through the book to look inside. If you did not get to this point you were unlikely to get a sale.

Nothing has changed! If a potential customer spots your book on a website it is still the Cover and the “short description” of the book that will clinch the sale… or not. You have to spend a lot of time on the design of both your Cover and the description of the book if you want to entice people to buy.

A New Hurdle – Quality

In the traditional printed book business almost all books were produced by Mainstream publishing houses. They all went through the same process: editing, proofreading, professional layout and more proofreading before they were printed and then quality control processes before being distributed. The final result was very similar for all books ‑ they were clearly printed, easy to read, had few typos and there was nothing ‘physical’ that would disrupt the reader’s enjoyment of the book. Final quality was never an issue that could be used to judge a book and the average quality of books was considered to be Good or Excellent. This has changed.

If your customer is attracted by your cover, and is then drawn in by your carefully worded ‘short description’ of the book the next stage is to open the book and look inside. ‘Look Inside’ is available for most books for sale through the big Ebook distributors. What do you think happens if the potential customer looks inside? If the formatting is poor, there is no Table of Contents, the pages all run together or the book is full of odd symbols instead of the correct text… It looks like a car crash and your customer will move on and dismiss your book without ever reading a word!

Quality is rapidly becoming one of the key issues affecting sales performance. If you want to compete successfully in a market with lots of nice looking books, you have to go through the same quality checking processes as the Mainstream Publishers and make your book just as good looking.

What are the biggest concerns about digital books?

In a 2014 survey of Ebook publishers:

  • 68% said quality affected sales.
  • Less than 50% of those who read Ebooks classed the average quality of books they had read as “good” or “excellent”.
  • 97% of publishers said that editing and proofreading were ‘as important’ or ‘more important’ for Ebooks as for print books.
  • 47% of publishers are planning to use the EPUB format and 41% plan to use MOBI (not clear how many will use both!).

The survey on “Trends in the Digital Publishing Industry” was done by (Data Conversion Laboratory) and Bowker (who manage the ISBN allocations in the USA) and found that Quality was one of the biggest concerns. You can read/download the detailed results here:

Keep in mind that if selling books was easy then all you would need to do with your manuscript would be to have it photocopied, give copies to booksellers and wait for the money to roll in. We all know that this doesn’t work, and the reason is that our customers have expectations about how a book should look and feel. There is a mutual relationship that needs to develop: if we don’t satisfy their needs they will not satisfy ours, and buy the book.

The conclusion to draw from Part 1 is that you must deliver a good looking book to your customers. If we do not meet their expectations they will have no reason to buy. A great book that is badly presented will not reach its potential.

The next article will be looking at the Anatomy of an Ebook and then David will move through how to use your software to produce a better result.


Ebook Dr 1

After over 30 years as a senior executive across the cable, telecommunications and cable television industries, David Cronin founded the Indie Publishing company Moyhill in 2004. Already involved with computers since the mid 1970s he quickly made the transition to book designer and publisher and the first book that Moyhill published in 2004, The Red Tailed Hawk, in Spanish won best digital print book in the UK that year.

Since then Moyhill has set up authors as their own publishers and has formatted several award winning novels and non-fiction titles.  It is essentially a one-man operation and this enables a one-to-one relationship with authors throughout the entire process.

Since the evolvement of Ebooks it has become clear that whilst most text books are reasonably straightforward to self-publish there are final touches that are beyond either the author or the software used.  This has led to a new service that is provided. The Ebook Clinic where those problems can be corrected and the Ebook re-uploaded.  There is no charge to identify the problems and because of demand the charges are low. For example £35 to adjust a text only (without tables of photographs) book up to 70,000 words.  Over the next week or so David will be providing the information and training to enable you to format and publish your own books.  If after that you feel you need more assistance to give your book a final polished format then you can contact him direct on


©DavidCronin 2015