A paperback interior has to do two jobs at once: it has to be comfortable to read, and it has to pass the print-on-demand upload without errors. Most of the problems writers hit, such as text too close to the spine, odd page counts, a trim size that does not match the cover, come from setting up the file in the wrong order. This guide sets out the order: choose a trim size, set margins that account for the spine, arrange the front matter, start the story on a right-hand page, add running heads and page numbers, and check the file. It is written around Amazon KDP, but the logic applies to any print-on-demand service. The last section covers what Quillen's print export does for you, which is all of it: you do not set anything by hand.
The short answer
Decide your trim size first, then set the margins (the inside margin has to be wider than the outside, and wider still for thicker books), order the front matter, start Chapter 1 on a right-hand page, put page numbers and running heads in the body only, and finish with an even page count. Quillen's Print, eBook & Kindle export sets up the book-style furniture (front matter, right-hand start, running heads, page numbers) in Word or PDF, to the standard, so there is nothing to set up by hand: you choose your options, export and upload.
Step 1: Choose a trim size
Trim size is the finished page size. Common choices for fiction are 5 x 8, 5.25 x 8, 5.5 x 8.5 and 6 x 9 inches. Smaller trims suit genre fiction and feel like a mass-market book; 6 x 9 suits most nonfiction and many novels. The trim size changes your page count (a smaller page means more pages), which in turn changes your printing cost and your spine width. Pick it before you do anything else, and use the same size for the cover. Our guide to choosing trim size and paper type has the trade-offs.
Step 2: Set the margins
In a bound book, part of each page disappears into the gutter next to the spine. KDP therefore sets a minimum inside margin that depends on the page count, with the outside margin smaller. The minimums on the KDP help pages at the time of writing are:
| Page count | Minimum inside (gutter) margin | Minimum outside, top and bottom |
|---|---|---|
| 24 to 150 pages | 0.375 in | 0.25 in (0.375 in if the pages have bleed images) |
| 151 to 300 pages | 0.5 in | 0.25 in |
| 301 to 500 pages | 0.625 in | 0.25 in |
| 501 to 700 pages | 0.75 in | 0.25 in |
| 701 to 828 pages | 0.875 in | 0.25 in |
These are minimums. A comfortable book uses much more: 0.75 to 1 inch outside and top, and a gutter a little wider than the minimum. Check the current numbers on KDP's formatting help page before you finish, because the minimums can change. Set the inside margin using "mirror margins" in Word, so that the wide margin sits next to the spine on both left and right pages.
Step 3: Choose a readable body style
Use a serif typeface at 10.5 to 12 points, with single spacing or a line height of about 1.2 to 1.4, and a first-line indent of about 0.25 to 0.3 inch rather than blank lines between paragraphs. The first paragraph after a chapter heading or a scene break usually has no indent. Justified text looks tidy in print if hyphenation is on; left-aligned is safer if it is not.
Step 4: Order the front matter
Front matter follows a conventional order, and each element starts on its own page:
- Half-title or title page (the book's title, sometimes the subtitle and author)
- Other books by the author (optional, often placed here or at the back)
- Title page with the author name and publisher
- Copyright page, on the back of the title page
- Dedication
- Epigraph
- Contents (nonfiction usually, fiction occasionally)
- Map or other illustrations, if any
Front matter pages are normally unnumbered, or numbered in lowercase roman numerals. Keep them short: the reader should reach the story quickly. Our guide to front and back matter covers the wording of each page.
Step 5: Start the story on a right-hand page
In a printed book, odd-numbered pages are on the right. The first page of Chapter 1 traditionally falls on the right, with page number 1. Chapters can start on either side after that, though many publishers start every chapter on a right-hand page, leaving a blank left page when needed. Starting new chapters on a new page is the safest choice for a print book.
Step 6: Add running heads and page numbers
A running head is the small line at the top of the page. The common pattern is the author's name on the left-hand pages and the book's title on the right-hand pages, with the page number at the foot or the head. Leave the chapter-opening pages without a running head, which is a convention that many layout tools handle automatically. Do not put running heads on front matter, and do not number the front matter as part of the body.
Step 7: Check the page count
KDP rounds up to an even number of pages, and a paperback must have at least 24 pages. If your book ends on an odd page, the file gains a blank page. Check the final page count, because it determines the spine width and so the cover; see how to calculate spine width. If you adjust the interior after designing the cover, recheck the spine.
Step 8: Preview before you publish
Upload your interior to KDP and use its previewer, which shows the pages as they will print, with the margins marked. Check every chapter opening, the first and last pages, any images, and the page where the text is closest to the gutter. If the previewer flags margin errors, increase the inside margin and re-export.
Common mistakes
| Mistake | Problem | Fix |
|---|---|---|
| Setting the trim size after finishing the interior | Reflow changes the page count and the spine | Choose it first |
| Equal margins on both sides | Text swallowed by the gutter | Mirror margins with a wider inside margin |
| Using the minimum margins | A cramped, cheap-looking page | Use generous margins |
| Blank lines between paragraphs in fiction | Looks like a web page, not a book | Use a first-line indent |
| Page numbers on front matter | Confusing numbering | Number from Chapter 1 |
| Odd page count | A blank page added at the end | Check the final count |
| Not previewing | Errors found after upload or after printing | Use KDP's previewer |
Do it in Quillen
Quillen's Print, eBook & Kindle export builds the book-style parts of a print interior for you: front matter, a right-hand start for the story, running heads and page numbers. The export is done to the standard, so you do not need to set page sizes, margins or page numbering yourself. The steps below are all there is to it.
- Open the export. Click Export in the header and choose Print, eBook & Kindle.
- Switch on the front matter you want. Tick Title Page, Copyright, Other Books, Dedication, Contents, Epigraph and Map as needed, and fill in each one. Each page appears in the preview.
- Open Style & Layout. Choose a chapter heading style, and decide whether to turn on a drop cap and running heads and page numbers. With running heads on, the author's name heads left-hand pages and the title heads right-hand pages, the page number is centred at the foot, and the body starts on a right-hand page numbered from 1. This applies to Word and PDF only.
- Check the Book preview. Click Book above the preview to see a two-page spread, and page through it with the arrows.
- Choose Word (.docx) and click Export. Choose Word if you want an editable file, or PDF for a fixed one.
- Upload to KDP. Use KDP's previewer to confirm the margins and the page count.
If you want to see how the cover and spine depend on the interior, use the page count from the finished file in the paperback cover editor.
Checklist
- Trim size chosen first and used for both interior and cover.
- Inside margin at least the KDP minimum for your page count, preferably more.
- Mirror margins turned on.
- Front matter in the conventional order, with no page numbers.
- Chapter 1 starting on a right-hand page, numbered 1.
- Running heads and page numbers on the body only.
- An even final page count, rechecked against the spine width.
- Previewed in KDP's previewer before publishing.
Common questions
What margins does a KDP paperback need?
The inside margin depends on page count, from 0.375 inch for 24 to 150 pages up to 0.875 inch for 701 to 828 pages, with at least 0.25 inch outside. Check KDP's current help page, and use more than the minimum.
Should the first chapter start on a right-hand page?
Traditionally yes. In a printed book the first page of Chapter 1 falls on the right and is numbered 1.
Does Quillen export a trim-size interior?
Quillen's Print, eBook & Kindle export is done to the standard, with book-style front matter, running heads, page numbers and a right-hand start. You do not need to set page size or margins yourself.
Why does my page count need to be even?
KDP rounds paperbacks up to an even number of pages, so an odd count adds a blank page. The final count also sets the spine width.
What running heads does Quillen use for print?
With running heads on, the author's name heads left-hand pages, the title heads right-hand pages, and the page number is centred at the foot.