How to format a book for KDP and IngramSpark (step by step)

To format a book for KDP and IngramSpark, set a fixed trim size, build inner (gutter) margins wide enough for the binding, add bleed only if artwork reaches the edge, embed every font, and export a press-ready PDF — one interior file and one cover-wrap file sized to your exact page count. Both accept broadly the same PDF, so build to the stricter spec.

What does formatting a print book actually mean?

A Word document is not a printable book. Formatting — typesetting, properly speaking — turns your finished, edited manuscript into two files a print-on-demand machine can read without complaint: an interior PDF (every page of text and images) and a cover PDF (back, spine and front as one flat wrap). Both platforms want a PDF, and both reject files that break their geometry — but the underlying rules are the same physics, so a file built carefully for one will almost always pass the other. The figures below are the conventions we work to, but printer specs change: confirm current numbers against each platform’s published guides and, always, against a physical proof.

Step 1 — Choose your trim size

Trim size is the finished page dimension after the printer cuts the sheet. Pick it first, because everything else (margins, spine, cover) is calculated from it, and changing it later means reflowing the whole book. For most fiction and general non-fiction, 5"×8", 5.25"×8" and 6"×9" are the safe, widely stocked sizes. Both platforms support a similar core range; IngramSpark’s catalogue of available trims is broader, which matters for poetry, art and gift editions. If you are matching an existing series, copy the previous book’s exact trim. Our trim-size reference lists the common options, and the book specs page collects the rest.

Step 2 — Set margins and the gutter

The single most common interior mistake is margins that crowd the spine. A bound book curves into its binding, so the inner margin (the gutter) must be wider than the outer one, or readers fight the page to read the words nearest the spine. The gutter also grows with page count: a 600-page book swallows more of the inner edge than a 200-page one, because the thicker the block, the more it curves.

As a rule of thumb, outer, top and bottom margins of roughly 13–19 mm (about 0.5–0.75") and an inner margin that starts there and increases with thickness will keep you safe. Treat that as a starting point, not gospel — POD printers publish minimum-margin tables keyed to page count, and you should check yours. Keep all live text well clear of the trim edge so nothing important sits where the blade lands.

Step 3 — Decide whether you need bleed

Bleed is artwork deliberately extended past the trim line so that, after cutting, colour runs cleanly to the edge with no white sliver. If nothing in your interior touches the page edge — a standard text-only novel — you do not need bleed at all. If you have full-page images, photographs or chapter backgrounds that reach the edge, every such element must extend past the trim on the bled sides, and your page size must be set up to include that extension. Forgetting bleed, or adding it inconsistently, is a classic rejection. Children’s books, cookbooks and illustrated titles almost always need it; most prose does not.

Step 4 — Embed every font

If a font is not embedded in your PDF, the printer’s system may silently substitute another, and your careful typography turns to a default face — or the file is rejected outright for missing fonts. Both KDP and IngramSpark require fully embedded fonts. When you export, choose the setting that embeds all fonts (and, ideally, that flags any it cannot), then open the finished PDF and check the document’s font properties to confirm every face reads as Embedded or Embedded Subset. Avoid fonts whose licences forbid embedding.

Step 5 — Get your images right

Two things sink image-heavy interiors. First, resolution: what looks crisp on a 72-dpi screen prints as mush — print wants around 300 dpi at the final printed size. Second, colour space: screens are RGB, presses are CMYK, and sending RGB into a colour print job can shift your tones (that vivid blue prints dull). Black text should be set as true black, not a four-colour mix. If colour fidelity matters to your book, this is worth handing to someone who manages it daily.

Step 6 — Export a press-ready PDF

Export, do not “print to PDF” casually. Aim for a single PDF with the correct page size, every font embedded, images at full resolution, the right number of pages (front matter included, blank pages where the layout needs them so chapters open on the correct side), and no interactive layers. A PDF/X export profile is a reliable target. Both platforms run your file through an automated preflight; build to the stricter spec and the same interior usually clears both.

Step 7 — Build the cover wrap from your page count

The cover is one flat file — back cover, spine, front cover, left to right — and its width depends on your final page count and paper stock, because those decide how thick the spine is. You cannot build the cover until the interior is finished and its page count is locked. Spine width is a calculation, never a guess: guess it and the wrap prints off-centre, with the spine text creeping onto the front. Crucially, KDP and IngramSpark use different spine and cover-template maths, so you generally need a separate cover file built to each platform’s template even when the interior is shared. Download the template for your exact trim and page count from the platform, or use our spine-width calculator to estimate it, and always include the bleed the cover template asks for.

How do KDP and IngramSpark specs differ?

Both want an embedded-font PDF interior and a flat cover wrap, and both honour the same margin and bleed physics. The practical differences are about distribution, ISBNs, tolerances and cover templates rather than the core file. This table summarises the points authors trip over most; treat the numbers as conventions to confirm against each platform’s current documentation, not fixed law.

Point	Amazon KDP	IngramSpark
Interior file	Press-ready PDF, fonts embedded	Press-ready PDF, fonts embedded (PDF/X commonly expected)
Cover file	Single wrap PDF from KDP template	Single wrap PDF from IngramSpark template (different maths)
Spine calculation	KDP’s own calculator/template	IngramSpark’s own calculator/template
ISBN	Free KDP-assigned ISBN available, or use your own	Your own ISBN effectively required for wide distribution
Trim range	Common sizes well covered	Broader catalogue, more specialist trims
Distribution	Amazon stores primarily	Wide trade distribution to shops and libraries
Setup fees	Free to publish	Free title setup as of 2026 (small per-sale distribution fee; check current pricing)
Best used for	Amazon reach and quick iteration	Bookshops, libraries, non-Amazon retail

Many authors publish through both — KDP for Amazon reach, IngramSpark for everywhere else — which means one interior built to the stricter spec and two cover files. If you are still weighing the choice, our deeper comparison, KDP vs IngramSpark, walks through the trade-offs.

What are the most common reasons files get rejected?

Print failures are boringly predictable, and nearly all of them are caught before a press ever sees the file:

• Spine width guessed, not calculated — the cover wraps off-centre and the spine text drifts onto the front.
• Missing or inconsistent bleed — edge artwork that does not extend past the trim leaves white slivers after cutting.
• Inner margin too tight — text curves into the binding and becomes a struggle to read.
• RGB images in a print PDF — colours shift on press instead of printing as intended.
• Low-resolution images — anything well under about 300 dpi at printed size looks soft or pixelated.
• Fonts not embedded — substituted faces or an outright rejection.
• Wrong page count or page parity — chapters opening on the wrong side, or a spine built before the interior was final.

The honest truth: you can learn all of this. Many authors do try, lose a week to it, order a proof, and find a mistake they did not know to look for. Whatever route you take, order a physical proof before you publish — screens lie about colour, trim and spine width, and a proof copy is the cheapest insurance you will ever buy.

Is it worth doing yourself?

If your book is straight prose and you enjoy fiddling with software, a clean text-only interior is within reach. The moment you add images, colour, an unusual trim or a dual KDP-and-IngramSpark release, the margin for error widens fast — and a wrong file is only discovered after the box arrives. That is the part most authors are glad to hand over.

At Librum we build interiors and covers to the published specs of both KDP and IngramSpark, with the spine calculated from your exact page count and every font embedded — files made to clear preflight the first time, with the editable source kept yours. If you would rather spend your week writing than wrestling export settings, see our print preparation service or tell us about your book on the contact page.