Print formatting has precise technical requirements that ebook formatting doesn’t share. Get your trim size, margins, header and footer setup, and PDF export settings wrong and KDP will either reject your file or print a book that looks unprofessional. This guide covers every requirement in detail.
| 10-minute read | All levels |
Print book formatting is a fundamentally different discipline from ebook formatting. Where an ebook is a reflowable document designed to adapt to any screen, a paperback is a fixed physical object with exact dimensions, specific paper stock, and a binding method that affects how much space the inner margin needs to be. Every layout decision in print formatting — margin widths, font size, line spacing, header placement — affects both the reading experience and the printing cost. Understanding these requirements before you build your document saves hours of rework and prevents the upload rejections and proof copy disappointments that catch too many self-published authors off guard.
Before any formatting work begins, your manuscript must be finished and proofread. Changes to the text after formatting is complete — even small ones — can cause text to reflow across pages, throwing off page counts, chapter breaks, and running headers. Vappingo’s manuscript proofreading service provides the thorough final review that lets you hand off to formatting with confidence that the text is locked in and correct.
Choosing Your Trim Size
Trim size is the physical page dimension of your finished book — what a reader holds in their hands. KDP supports a range of trim sizes; the most commonly used for trade fiction and non-fiction are 5″ × 8″, 5.5″ × 8.5″, and 6″ × 9″. Each has different implications for page count (and therefore printing cost and royalty), physical feel, and reader expectations.
A 5″ × 8″ trim produces a compact book that feels similar in hand to a mass-market paperback. For the same word count, it will have more pages than a 6″ × 9″ trim, which increases printing cost but can make a short book feel more substantial. A 6″ × 9″ trim is the standard for most business, self-help, and instructional non-fiction — it feels like a trade paperback and accommodates tables and diagrams well. A 5.5″ × 8.5″ is the middle ground, often used for literary fiction and narrative non-fiction.
Your trim size choice has a direct financial consequence through printing cost. KDP’s printing cost formula is: Fixed Cost + (Page Count × Per-Page Rate) = Printing Cost. A book formatted for 6″ × 9″ at 250 pages has fewer pages than the same word count formatted for 5″ × 8″ at 310 pages — and fewer pages means lower printing cost, which means either higher royalty per copy or more room to price the book accessibly. See the KDP Print Royalties guide for how printing cost interacts with your list price and royalty rate, including the June 2025 royalty structure change.
Setting Correct Margins
Margins for KDP print books are not aesthetic choices — they’re structural requirements determined by KDP’s printing process and binding method. Setting margins incorrectly is one of the most common reasons KDP rejects print file uploads.
The inside margin (the gutter — the edge facing the spine) must be wide enough that text isn’t lost in the binding. KDP’s minimum gutter margins by page count are: 0.375 inches for books under 300 pages, 0.5 inches for books 300–600 pages, and 0.625 inches for books over 600 pages. These are absolute minimums — professional book designers typically add 0.125–0.25 inches beyond the minimum for a more comfortable reading experience, particularly for longer books where the binding is stiffer and pages don’t lie fully flat.
Outside, top, and bottom margins must each be at least 0.25 inches. In practice, most professionally formatted books use 0.5–0.75 inches on these edges for comfortable reading. Margins that are too narrow make the text feel cramped and are one of the most visible markers of amateur self-published formatting. Margins that are too wide waste page space, increasing page count and printing cost unnecessarily.
In your Word or layout application, set your document page size to exactly your chosen trim size — not letter or A4 — and enable mirror margins so that the gutter appears on the correct side for odd (right-hand, recto) and even (left-hand, verso) pages. Failure to enable mirror margins means your gutter appears on the same side of every page, which makes the book impossible to read in its bound form.
Typography for Print
Body font size for most trade books is 10–12pt. Larger fonts feel more accessible but increase page count significantly — a full-length novel formatted at 12pt will have roughly 20–25% more pages than the same novel at 10.5pt. Most professional formatters for adult fiction and non-fiction use 10.5–11pt as a balance between readability and page economy. Children’s books and large-print editions use substantially larger body text (16–18pt for large-print editions) to serve their specific reader needs.
Line spacing (leading) for print body text is typically 1.1–1.3× the font size — tight enough to read as a flowing page without excessive white space, but generous enough to be comfortable for extended reading. Most formatting tools express this as a specific leading value (e.g., 13pt leading for 11pt body text). Setting line spacing in Word using the “Multiple” setting rather than “Exactly” or a percentage gives you the most reliable cross-font consistency.
Paragraph indents on body text are typically 0.25–0.375 inches. The first paragraph of each chapter, and the first paragraph after a scene break, are conventionally unindented (flush left) in most trade books — a typographical convention that dates to print publishing norms and that readers expect even if they can’t articulate why. Omitting the unindented first paragraph is one of the most common amateur formatting errors in self-published fiction.
Running Headers and Page Numbers
Running headers — the small text at the top of each page showing the book title, author name, or chapter title — are standard in most trade non-fiction and some fiction. They’re optional in fiction, where many publishers omit them for a cleaner look, but expected in most non-fiction. When used, the convention is: author name on left-hand (verso, even-numbered) pages, book title on right-hand (recto, odd-numbered) pages — or chapter title on the verso and book title on the recto for books with titled chapters.
Page numbers go in the footer, positioned at the outside edge — bottom right on odd pages, bottom left on even pages. First pages of chapters and blank pages should have no running headers and typically no page numbers, though the page count continues. In Word, implement this using separate header and footer sections for odd and even pages, with section breaks at each chapter opening to suppress the header and reset the footer on first pages. This is one of the more technically complex aspects of Word-based print formatting and a primary reason why dedicated formatting tools like Vellum, Atticus, or Adobe InDesign are worth their cost — they handle all of this automatically and correctly.
Exporting a Print-Ready PDF
Your final print file for KDP must be a PDF with specific export settings. The key requirements are: page size set to your exact trim size (not letter or A4 with crop marks), no printer marks or registration marks included (KDP adds its own), fonts fully embedded, colour mode RGB (even for black-and-white books — KDP converts to CMYK during printing), and compression settings that preserve image quality at minimum 300 DPI.
In Word, export using “Save as PDF” or “Print to PDF” with your page size set correctly and margins as configured. Do not print to a PDF driver that adds virtual paper size around your document — the PDF page size must equal your trim size exactly. In Adobe InDesign, use “Export as PDF/X-1a” for the most reliable print-ready output. In Vellum or Atticus, the print PDF export handles all settings automatically — choose your trim size and the tool manages the rest.
After exporting, validate your PDF by opening it and checking: page dimensions match your trim size exactly (visible in your PDF viewer’s document properties), all fonts show as embedded (also in document properties), the first interior page is page 1 (right-hand), and margins look correct across a sample of pages including chapter openings and mid-chapter pages. Then upload to KDP and use the Online Previewer to inspect the final rendered result before ordering a proof.
Ordering a Proof Copy
Before your book goes live for sale, order at least one printed proof copy. KDP allows you to order proof copies at printing cost during the review stage, before you approve the book for sale. A physical proof reveals issues that no digital preview can show: how the actual paper colour affects the interior pages, how the spine text looks at printed size, whether the cover image is as vivid in print as on screen, and whether the font feels comfortable at its chosen size on the actual paper stock.
Ordering a proof is one of the most valuable steps in the print publishing process and costs only a few pounds or dollars plus shipping. The Alliance of Independent Authors maintains useful guidance on what to check in a proof copy at allianceindependentauthors.org — covering both interior and cover inspection. Plan your publication timeline to include 10–14 days for proof delivery and review before your intended launch date. The Book Launch Checklist covers how proof review fits into the overall pre-launch timeline.
Headers, Footers, and Page Number Conventions
The header and footer system for a professional print book follows conventions that trade publishers have used for decades — conventions readers have absorbed without consciously noticing them, but that they notice when violated. Running headers typically alternate: author name on verso (even-numbered, left-hand) pages, book title on recto (odd-numbered, right-hand) pages. Page numbers appear in the outside footer — bottom right for recto, bottom left for verso. Chapter opening pages and blank pages have no running header and often no page number (though the page count continues). The front matter — everything before chapter one — uses Roman numerals (i, ii, iii) for page numbers; the main text resets to Arabic numerals (1, 2, 3) starting from page one of chapter one.
Implementing this correctly in Word requires: enabling mirror margins, setting “different odd and even pages” for headers and footers, inserting section breaks between the front matter and the main text to reset page numbering, and using the “Link to Previous” toggle carefully to prevent header changes in one section from affecting the previous section. Word’s section break and header/footer system is functional but complex — this is the part of Word-based print formatting that most commonly produces errors in self-published books. If you find this process frustrating, it’s a strong argument for using a dedicated formatting tool for print.
Black and White vs Cream Paper
KDP offers two paper options for most print formats: white paper and cream (sometimes called natural or off-white) paper. Cream paper is the traditional choice for fiction and literary non-fiction — it’s easier on the eyes for extended reading, reduces eye strain from high-contrast black type on bright white, and is the paper type used by most traditional publishers for trade fiction. White paper is standard for non-fiction with charts, photographs, or diagrams where true-white reproduction matters, and for books where a clean, modern presentation is part of the design intent.
Your paper choice affects your printing cost slightly (cream and white paper cost the same for most KDP trim sizes) but affects how colours appear in your interior if you’re using grey tones or light shades — these read differently on cream paper than on white. If you’re printing in black and white with any gradient elements or light grey shading, check how these render on your chosen paper by ordering a proof copy before committing. The Alliance of Independent Authors maintains practical guidance on print production decisions including paper choice at allianceindependentauthors.org. Your paper choice should also inform how you price your book — see the KDP Print Royalties guide for how printing cost interacts with your list price after the June 2025 royalty structure change.
Final Formatting Checklist Before Upload
Before uploading your print PDF to KDP, work through this checklist. Page size in the PDF matches your trim size exactly — not letter, not A4, not letter with crop marks. Margins meet KDP’s minimum requirements for your page count and include adequate gutter space. Fonts are fully embedded in the PDF. All text elements are within the safe zone (at least 0.125 inches inside the trim line). Chapter opening pages have no running header. Page numbers appear in the correct outside-edge position. If using bleed, bleed extends 0.125 inches beyond the trim on all applicable edges. All images are at minimum 300 DPI at their printed size. The first interior page is a right-hand (recto) page — typically the title page or chapter one opening.
Your Manuscript, Professionally Prepared
Text changes after formatting is complete cause expensive reflowing and rework. Vappingo’s manuscript proofreading service delivers a clean, verified text that’s ready for the formatting stage — with no surprises.
