A reader never opens your manuscript file. They open a book, and they meet it one page at a time — the weight of the margins, the way a chapter begins, the quiet rhythm of a page number in the same place every time. The interior is everything inside the cover, and formatting it well is the difference between a book that reads like it was made and one that reads like a document that was printed.
The good news is that none of it requires a designer, and none of it requires taste you do not already have as a reader. A professional book interior is mostly a set of conventions, applied consistently. This guide is the map: it walks the whole interior at a high level, in the order the work actually happens, and points to a closer look at each part where you want one. Format your book this way and it will read like a publisher made it — not because of any single flourish, but because every page agrees with every other page.
Start with the page itself
Before a single word is placed, the page has a shape and a frame. The shape is the trim size — the finished width and height — and it governs everything downstream, which is why it is worth choosing a book trim size before you format anything else. The frame is the set of margins inside that page: the white space that holds the text block away from the edges and away from the binding.
Margins are not decoration. The inner margin, the gutter, has to be wide enough that words do not vanish into the spine when the book is held open, and it has to grow as the book gets thicker. Amazon KDP sets minimums for both the outer margins and the gutter, and getting them wrong is one of the most common interior faults. The full picture — including the figures KDP requires — is in margins and the gutter. Settle the page first; the text has to know its room before it can fill it.
Put the front matter in order
Open almost any published book and the story does not start on page one. A short sequence of pages comes first — the half-title, the title page, the copyright page, perhaps a dedication, then the contents — and they fall in a conventional order that readers recognise without thinking about it. The same is true at the back: acknowledgements, an about-the-author page, a list of other titles.
These pages are easy to assemble badly, in the wrong order or with pieces missing, and just as easy to get right once you know the running order. Front matter and back matter: what goes where lays out the whole sequence and what belongs on each page, including the one page no book should ship without.
Make the chapters begin like chapters
A chapter opening is a small piece of stagecraft. The new chapter drops down the page rather than starting at the top — the white space above the title is called the sink — and the first line often carries a raised or dropped capital. The running head is suppressed on that page, because a title sitting above a chapter title is clutter. None of this is fussy; it is simply how a reader is told a new thing begins here.
Done consistently, chapter openings give a book its sense of pace. Done carelessly — every chapter starting at a different height, headings styled four different ways — they make a book feel improvised. Formatting chapter openings and headings covers the sink, the drop cap, heading levels and how to keep them consistent across a whole manuscript, for fiction and non-fiction alike.
Number the pages and run the headers
Every page below the chapter openings carries two small marks: a page number — the folio — and a running head, the line of type at the top that names the author on one page and the book or chapter on the facing one. They seem trivial, and they are where amateur interiors most often give themselves away: a folio that drifts, a running head printed on a blank page, numbering that counts the title page as page one.
The conventions here are firm and worth following exactly. Page numbers and running headers, done right sets out where each one sits on a two-page spread, which pages suppress them, and the front-matter numbering that trips most people up.
Build a contents page that actually works
If the book has chapters or sections, it needs a table of contents — and a contents page is two different objects at once. In print, it is a typeset page where each entry points to a folio. In an ebook, it is a navigation structure of links, with no page numbers at all, because an ebook has no fixed pages. A contents page that works on paper can be quietly broken on a Kindle, and the reverse.
This is more involved than it first appears, which is why building a table of contents that works takes it on its own: manual versus automatic, print versus ebook, and the handful of reasons a contents page breaks on upload.
The order it all happens in
Laid out as a sequence, the interior comes together like this:
- Fix the page — trim size, then margins and gutter.
- Assemble the front matter — half-title through contents, in order.
- Style the chapters — openings, headings, the sink and drop cap, applied consistently.
- Set the running heads and folios — suppressed where they should be, numbered correctly.
- Generate the contents — once the chapters are settled, so the entries are accurate.
- Add the back matter — acknowledgements and the rest.
The order matters because the later steps depend on the earlier ones. A contents page built before the chapters are final lists the wrong pages; running heads set before the front matter is in place number from the wrong point. Work top to bottom and each step rests on solid ground.
Why consistency is the whole job
What separates a professional interior from an improvised one is not a single dramatic choice. It is that every chapter begins at the same height, every running head reads the same way, every folio sits in the same spot, and the margins are identical from page two to page two hundred. A reader cannot name any of this, but they feel it — the book holds together, or it does not.
The interior is one half of the print-ready book. The other half is the cover, whose full-wrap size is built from the same trim and page count the interior produces — how to calculate your KDP cover size correctly is its companion, and together they make the finished object. Get the interior right first; the cover is built to fit it.
Where Folio Format fits
Consistency is exactly what a general word processor makes hard, because it treats a book as a long document rather than a set of pages that have to agree with one another. This is the work Folio Format is built to carry, and it is the reason indie authors reach for a dedicated studio rather than a general one: the trim, the margins, the chapter style, the running heads, the folios and the contents are all properties of the one book file, applied across every page at once and exported together for Amazon KDP, IngramSpark and your wider archive. Folio carries the manuscript from first draft to print-ready PDF, DOCX and ePub from one local workspace — designed to help you export KDP-ready files and catch common publishing issues before upload, so the interior that leaves your desk reads the way a finished book should.
Last checked 26 May 2026. Always confirm current Amazon KDP and IngramSpark specifications before uploading final files. Folio Format is designed to help users export KDP-ready files and catch common publishing issues before upload; it makes no claim about platform acceptance.