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We show the measurements. Every print claim points at a row.

Here the proof is an artefact you can read: a report run against the finished files, printing what was measured beside what the rule asked for, and naming whose rule it is. Every claim we make about print readiness points at one of its rows.

The artefact

The report is run against the finished files

Nothing on the report is an intention. Each check opens the rendered interior and cover PDFs, measures one thing, and records the value it found beside the value the rule asks for. The report is shown in the app beside the files it measured, before you download any of them, and the export pack carries a copy of it out alongside the files it describes.

Every report is stamped with the revision of our KDP specification table it was checked against, and it keeps that stamp for as long as the report exists. The stamp is what stops the proof quietly decaying into an assertion when Amazon changes a number.

14 of 14 checks passed on the interior and cover files

  • Every page is the trim size you chose

    Measured6 × 9 in on all 40 pagesRequired6 × 9 in on every page, within 0.25 pt

    Every page in the file is measured against the trim size you chose, because a paperback is printed and trimmed at one size for all of its pages.

    A rule Amazon KDP publishes · kdp-spec-v1 rows A2, B13

  • The inside margin is wide enough for the page count

    Measured29.16 pt at the closest measured ink, on page 8. The rendered image reads 28.44 pt, on page 16RequiredAt least 27.00 pt (0.375 in) for a book of 24 to 150 pages. At least 26.39 pt on the rendered image, which reads in pixel steps

    A thicker book needs more room at the spine, or the text disappears into the binding.

    A rule Amazon KDP publishes · kdp-spec-v1 rows B1 to B5

  • The outside, top and bottom margins clear the trim

    Measured30.82 pt at the closest measured ink, on page 8. The rendered image reads 32.40 pt, on page 8RequiredAt least 27.00 pt (0.375 in) from the outside, top and bottom edges. Artwork meant to bleed runs at least 9.00 pt past the trim. At least 26.39 pt on the rendered image, which reads in pixel steps

    Cutting is not exact, so text has to sit far enough from the edge to survive it.

    A rule Amazon KDP publishes · kdp-spec-v1 rows B6, B7, B11

  • Bleed is either on every page or on none

    Measured6.125 × 9.25 in with bleed on all 40 pagesRequired6.125 × 9.25 in with bleed: 0.125 in at the top and bottom, 0.125 in on the outside, none at the spine

    Mixing bleeding and non-bleeding pages produces a book with uneven edges.

    A rule Amazon KDP publishes · kdp-spec-v1 rows B8, B8a, B9, B11

  • Every font is embedded in the file

    Measured8 fonts across 2 files, all embedded in fullRequiredEvery font embedded in full, with every glyph of the source font

    A font that is only installed on your computer prints as something else, or not at all.

    A rule Amazon KDP publishes · kdp-spec-v1 row B10

  • The print files use print colour

    MeasuredNo RGB or Lab colour in either fileRequiredNo RGB or Lab colour in the interior or the cover

    Screen colour and print colour are different systems, and a press needs the print one.

    Our own rule · kdp-spec-v1 rows E2, D21

  • Every image is sharp enough at the size it is placed

    MeasuredNo images placed in either file, read two waysRequiredAt least 300 ppi at every placed image, read two ways

    An image that looks fine on screen can print soft if it is stretched.

    A rule Amazon KDP publishes · kdp-spec-v1 rows E3, E4

  • The spine width matches the page count

    Measured0.1000 in (7.200 pt)Required0.1000 in: 40 pages at 0.0025 in each, within 0.001 in

    The spine is calculated from the pages and the paper, so the cover wraps where it should.

    A rule Amazon KDP publishes · kdp-spec-v1 rows D2, D7, D11

  • The barcode area is clear

    MeasuredNothing printed in the barcode area, read two waysRequiredNothing printed in the barcode area, placed where KDP's own cover template for this trim puts it

    The printer places a barcode on the back cover, and artwork underneath it is a rejection.

    Our own rule · kdp-spec-v1 rows D15, D16, O5

  • Spine text follows the page-count rule

    MeasuredNo spine textRequiredNo spine text at 40 pages, and this spine has no room for any

    A thin book has no room for spine text, and text too near the fold prints on the front or back.

    A rule Amazon KDP publishes · kdp-spec-v1 rows D18, O6, D19

  • No printer marks, and the file is flattened

    MeasuredNo annotations, transparency, printer marks or ink past the bleedRequiredNo annotations, transparency, printer marks or ink past the bleed

    Crop and registration marks belong to a press proof, not to an uploaded file.

    A rule Amazon KDP publishes · kdp-spec-v1 rows D22, E7, B12

  • The file matches the PDF/X-1a profile

    Measured44 of 44 PDF/X-1a checklist items passRequiredEvery item of the PDF/X-1a:2001 checklist, interior and cover

    A single printing profile with everything embedded, which is what a press expects.

    Something Amazon recommends rather than requires · kdp-spec-v1 rows E1, O8

  • The back matter is present, and each QR code keeps its quiet zone

    Measured3 of 3 back-matter headings, no clickable links. This book declares no link and no QR codeRequiredEvery heading present, no clickable links, every short address printed as text, and no QR code expected, since the book declares none

    A printed book cannot carry a clickable link, so addresses are printed as text and, where the book carries one, as a QR code. This checks that each code matches, module for module, the address it was made for, and that nothing is printed in the margin of blank paper around it, called the quiet zone.

    Our own rule · no kdp-spec-v1 row covers it

  • The margin calculation settled

    MeasuredSettled at 40 pages after 1 passRequiredSettled within 4 passes, at the page count of the file and a gutter wide enough for it

    Margins depend on the page count, and the page count depends on the margins. This says the loop reached a fixed answer.

    Our own rule · kdp-spec-v1 rows B1 to B5

A real report on a 40-page book built during development, 4 September 2026.

One row

What a single row shows

A row names the check in plain language, says why it matters for a printed book, and opens to show four things: the value measured in your file, the value the rule requires, what exactly was checked, and whose rule it is with the specification rows behind it.

A check that did not pass is shown first, opened, with its measurement already visible. The thing that tells you what to change is not hidden behind a click.

Whose rule

Whose rule each check enforces

Not every check is Amazon’s. Some are their published requirements, some are things they recommend, and some are ours because the published number is not enough to survive a real press. Blurring those together would be the easiest way to overstate what we prove, so every row carries one of exactly three labels.

A rule Amazon KDP publishes
Amazon states this requirement in its own specification. The row cites the table rows it came from.
Something Amazon recommends rather than requires
Amazon advises it rather than requiring it. A file that misses it can still be accepted; the report does not predict what Amazon will decide either way.
Our own rule, stricter than the published one
A tighter bar than a number Amazon publishes, each one with a recorded reason, and the row cites the published line it is tighter than. Spine text is the clearest: Amazon permits it above 79 pages, and we set it only where seven point type plus the clearance actually fits, so a book between 80 and 88 pages carries none and the row says why.
Our own rule
A check of ours with no requirement in the table of Amazon’s published specification to be stricter than. Some cover ground Amazon leaves unstated or only recommends: print colour in the interior, and the barcode area, which we read from Amazon’s cover template because its pages never state it. Others have no counterpart at all: the back matter’s printed links, and the record that the layout settled.

The limits

What the report does not claim

This is the part most pages leave out, so it is written in full.

It is not Amazon's decision
The report measures your file against a specification. Acceptance is Amazon's, made by their own review against policies they can change. A passing report is evidence, not an outcome. See the refunds page for how we handle a rejection after a pass.
We do not upload for you
There is no public KDP or Apple Books publishing interface for us to integrate with, so InkReady does not put your book on sale. You upload the files we hand you.
It measures the files, not the writing
The checks cover the interior and cover PDFs: their geometry, colour, fonts, embedded resources and the render records behind them. The quality of the prose is scored separately, against our own rubric, and that score is shown as what it is: provisional, and no substitute for reading your book.
It measures the files it was given
A report belongs to one render of one book. Edit the book and the report no longer describes what you have.
It says nothing about anybody else
We have not inspected a competitor's output, so we make no claim about it. What we say is what we measured in your file.

Going stale

An edit invalidates the report

Changing a chapter can change the page count, and the page count decides the gutter, the spine width and whether spine text is allowed at all. So any edit that can move the page count marks the report as no longer describing your files, and the page says so rather than showing you a stale pass.

Exporting runs the checks again on the files it is about to freeze. Every file in the pack is then read back out of storage and hashed a second time, and the download is refused rather than served if any of them is not the file the report measured. A pack you have already taken keeps describing the book as it was on the day it was frozen, and says so.

Fonts

The type in your book, and why you can sell it

Your interior is set in Source Serif 4 by Adobe, and the running heads, the cover and this site are set in Hanken Grotesk by Alfredo Marco Pradil. Both are released under the SIL Open Font License 1.1, which permits embedding them in a document you sell. That is the whole point of naming them here: a font licence that did not allow commercial embedding would make every file we hand you unsellable, and you would have no way of knowing.

You owe nobody a credit inside your own book. We checked each licence against the foundry’s own text before shipping, and any face we add later gets the same check first.

If a check on your report looks wrong, that is worth an email: support@inkreadyai.com, with the report id. A rule of ours being wrong is a thing we would rather find than defend. See also privacy and refunds and credits.