An EPUB file is a bundle of files. In the rune Studio export verified for this article, the body pages, contents, cover, and colophon were separate files inside. Knowing that verified structure is what lets you decide where a fix belongs when something breaks. EPUB in general does not require every publication to contain a cover and colophon as separate files.
This article uses an EPUB I actually built to show both what is inside and the order for finishing a book with contents, cover, and colophon. The point is to know what must be settled before moving to the next stage.
The finishing sequence for contents, cover, and colophon
Start with the series information: title, author, publisher, output file name, writing direction, and language. Then confirm the volume-specific information, including edition, publication date, and cover image. Run validation here so empty or incompatible settings are fixed before export.
Next, select the manuscript files and arrange them in reading order. Check where the title page, each chapter, and the colophon belong, then decide which chapters should appear in the contents. Reading order and inclusion in the contents are separate decisions, so a correct file order is not the end of the check.
Once the cover image and the information intended for the colophon are ready, review the selected manuscripts and their order, then build the EPUB. Production tools differ in how they construct a colophon, so read the resulting colophon as body text after export.
Finally, open the resulting EPUB. Check its files and the reading order recorded by the package document's spine, then read the contents, cover, and colophon pages themselves. Settings, source order, contents inclusion, cover, colophon, export, and checking the result together make up the finishing procedure.
An EPUB is essentially a folder
The extension is its own, but the contents behave like a folder. Unpack it and you find a defined set of folders and files.
Unpacking an EPUB exported from the rune Studio development build showed ten files:
Under the W3C EPUB 3.3 specification, META-INF/container.xml locates the package document, while the package document's spine defines the default reading order. They should not be collapsed into one “where reading begins” role.
- a small file identifying the format
- a file locating the package document that holds structure and metadata
- a stylesheet
- a file holding the book's structure and metadata
- the contents file
- body pages (chapter one, chapter two)
- the title page
- the colophon page
- a legacy navigation file for older reading systems
The contents and the colophon are each their own file. Once that is clear, "the table of contents is wrong" points to one specific file to inspect.
Fixing without knowing the inside is guesswork
Without that picture, fixing breakage becomes edit, export, open, look, repeat.
The trouble is you cannot confirm that what you changed matches the symptom. When a chapter is missing from the contents, the cause could be the heading in the manuscript, the contents file not being generated, or the reading app not using it — and each has a different fix.
What actually lands where
I read the contents of the exported file.
The structure and metadata file held title, author, publication date, language, publisher, and a unique identifier. It also recorded the text flow and the direction in which pages progress.
The contents file held chapter names paired with destinations, each pointing at a body page. The same ordering appeared in the legacy navigation file.
The colophon page held the title, the publication date and version, the author, the publisher, a copyright notice, and a fiction disclaimer, as readable prose.
Read the verified ten files by role
In this export example, opening and counting the package produced ten files. Because the body, contents, title, and colophon could be read separately, a fault can be assigned to a role before anything is edited. Ten is the result of this specific verified export, not a universal EPUB file count.
A cover adds one more
Exporting with a cover image added a cover page to the front of the reading order and to the entry count. A cover is a page too. Inspection lists it as an empty page while the verdict stays valid, because an image-only page has no text.
Images are renamed by page
Embedded images do not keep the file name written in the manuscript; they are renamed based on the page they belong to. Searching an unpacked EPUB for your original file names finds nothing — which is usually where manual reconciliation falls apart.
Knowing the structure decides the fix
Take "a chapter is missing from the contents". First open the EPUB and establish whether the contents file exists, then check whether the chapter is listed inside it. A missing file points toward generation; an existing file missing one chapter points toward the heading or inclusion decision. The guesswork loop shortens.
Who this suits, and who is fine without it
It suits anyone who wants to fix breakage themselves, including deciding what to change after a store rejection.
You can publish without knowing any of this. If things are going smoothly, there is no need to memorise it — read it back when you get stuck.
Scope note: what was verified is one EPUB's contents and one inspection result. Not every EPUB has this structure — the number and names of files vary by the tool that produced them.
Summary
- An EPUB is a bundle of files; the example verified here contained ten
- The contents and the colophon are each their own file
- The structure and metadata file holds title, author, date, language, publisher, and the reading direction
- Finish in this order: series information, source order and contents inclusion, cover, export plan, then inspection
- Knowing the structure lets you decide where a fix belongs
For a first step, complete the series information, arrange the manuscript files, choose what appears in the contents, and set the cover before exporting one EPUB. Open it and compare the package spine and the actual pages with that plan; this checks the finished book rather than only the manuscript.
See the current product scope on the Rune Studio product page.
