Print Book Formatter and Typesetting Software for KDP-Ready Interiors

The gutter is the inside margin, next to the spine. A thicker book curves more near the binding, so more of the inside edge becomes hard to read — which is why KDP requires a larger inside margin as page count grows. We count your finished pages and apply the right one automatically.

The inside margin has to be on the left of a right-hand page and the right of a left-hand page, because the spine alternates sides. Getting this wrong is the most common reason a first proof looks wrong: text drifts toward the spine on every other page.

6\u00d7\u0039\u2033 is the default for most novels and non-fiction. 5\u00d78\u2033 and 5.5\u00d78.5\u2033 suit shorter books and feel more like a mass-market paperback. Pick the one you selected on KDP — changing it later changes your page count.

Only if something is meant to run off the edge of the page — a full-bleed image or a coloured background. A text interior does not, which is the usual case for novels, so we produce a no-bleed file.

It is the layout half of it. Typesetting covers how the type sits on the page — measure, leading, margins, where chapters open, how a page turn is handled — and that is what this produces automatically. What it does not do is the bespoke design work a human typesetter brings to an illustrated or unusual book. For a novel or a work of non-fiction that is mostly prose, the automated version is what you want.

Paperback today. Hardcover uses a different set of trim sizes and its own margin rules, and we would rather say so than hand you a file built to the wrong specification. If you are doing a hardcover edition, the geometry here will not be right for it.

The geometry is built to KDP's published requirements: standard trim sizes, their minimum inside margin for your page count, and embedded fonts. We would still order one proof copy before a full run — see the note below.

Formatting is free. Free files include a small footer line, allow three adjustments, and are kept for 24 hours. Unlocking one file costs $5 once — no subscription — which removes the line, lifts the adjustment limit, and keeps the file for 7 days.