Where to check the technical print specifications required by each distributor or printer?

A book file can be technically perfect and still be rejected — because it was perfect for another printer. Each print supplier has its own requirements for bleed, margin, spine, colour and file format, and they are not interchangeable. The question "where do I check this?" has a different answer for each type of supplier, and this article goes through them all.

1. Print-on-demand platforms

Amazon KDP, IngramSpark and the Brazilian POD services publish their specifications publicly and in a structured way. It is the simplest scenario, with one caveat: the rules change, and the only reliable source is the official site, consulted at the moment of delivery.

What to look for

• Help centre or formatting guide — the page describing accepted formats, bleed, margins by page count, minimum resolution, colour profile and PDF type.
• Cover template calculator or generator — the tool that takes the format, page count and paper type and returns a file (PDF or PNG) with the exact spine width, the bleed areas and the safe zones marked. The designer builds the cover on that template, not on a calculation of their own.
• Interior specifications — minimum margins, which grow with the page count, and the list of errors that cause the file to be refused in the automatic check.
• Available papers and weights — the paper type changes the spine thickness; choosing the paper is a decision that precedes the template.

What to avoid

Video tutorials, forum posts and shared spreadsheets with "the KDP measurements" go out of date without warning. They are useful for understanding the process, not for finalising the file. If a value in a tutorial and a value in the help centre diverge, the help centre wins.

The automatic check is not a review

POD platforms run a check that flags objective errors — text outside the margin, low resolution, wrong file size. It does not assess readability, leading, widows or image quality beyond the minimum. A file "approved" by the platform can be a poorly laid-out book. On the minimum values and what goes above them, see What is the minimum safety margin a designer should respect for offset and POD printing?

2. Offset printers

In offset printing there is no public help centre. The specification comes from the printer, for that quote, and the document has various names: "technical specifications", "file setup guidelines", "production brief" or simply a section of the quote itself.

When it doesn't come

Many printers send the quote without the technical document, and it is the designer's responsibility to ask. The request should be made before finalising the layout, not after — because the gutter, cover bleed and real format may fall outside the standard the designer assumed. A direct email solves it: "Before I finalise the file, I need the specifications for bleed, safe zone, gutter for X pages on paper Y, spine calculation, colour profile and accepted PDF format."

What must appear

• The trimmed and untrimmed format, in millimetres
• The required bleed (interior and cover) and the recommended safe zone
• The suggested gutter for the page count and binding type
• The spine calculation or measurement, with the chosen paper
• The colour profile (usually a CMYK profile specific to the paper — coated or uncoated) and the policy for RGB elements
• The minimum image resolution and the total ink coverage limit
• The accepted PDF type (PDF/X-1a, PDF/X-4) and whether the crop marks should or should not be in the file
• For covers with finishing: how to deliver the varnish, hot-stamping or embossing masks (separate layers, a named spot colour)

If the printer replies "send it however you think best", the designer can apply the market standards — but records in writing what was assumed, so a bad proof does not turn into an argument about whose decision it was.

The proof as final verification

In offset, the specification is confirmed on the proof. A contractual digital proof (printed on paper simulating the result) for the cover; a layout proof (PDF or a simple print) for the interior. It is there that you discover whether the gutter swallows text and whether the spine is aligned. On how to resolve discrepancies at this stage, see When the layout clashes with the printer's technical requirements, what should you do?

3. Distributors and publishers

When the book is produced for a publisher or goes through a distributor with its own printing, the specifications are internal: a production manual, a cover template or a collection standard. The external designer receives this material in the brief — and, if they do not, asks for it just as they would from a printer.

Publishers usually also have requirements that are not technical printing ones but affect the file: the position of the logo, the cataloguing-record and CIP text, the ISBN barcode at a defined size and position, the collection imprint. All of this enters the same checklist. On what the designer needs to receive to start, see What does the designer need to receive from the author or publisher to start a layout project?

4. When the book goes to more than one supplier

It is common for a launch to have an offset run for bookshops and POD for online sales, or to be on two POD platforms at once. In these cases:

• The designer gathers the specifications of all the suppliers before designing.
• The interior is designed for the most restrictive case — usually the largest gutter and the largest safe zone among them.
• The cover is built separately on each template, because the spine differs between papers and formulas.
• Each final file is named with the supplier and the date, so no one sends the KDP PDF to the printer.

One spine, one template

The same book with the same page count has different spines on Amazon, IngramSpark and at the printer, because the papers have different thicknesses. Reusing the cover from one platform on another without redoing the spine is the most frequent mistake in multi-channel launches.

On what changes in the layout between these processes, see How does the designer adapt a layout for different distribution formats, such as POD and offset?

5. A method for not missing anything

The process I use in any project, regardless of the supplier:

1. Before laying out: obtain the written specification (official page, printer's document or publisher's manual) and save it in the project folder, with the date.
2. When defining the project: check that the document's format, margins and bleed exceed the minimums of the specification.
3. When finalising the interior: generate the cover template with the final page count and the chosen paper.
4. At export: apply the colour profile, the PDF type and the marks exactly as specified, and run the preflight.
5. Before sending: go through the specification's checklist item by item — and, in offset, wait for the proof before releasing the run.

Step 1 is the one most often skipped and the one that costs the most. On the following steps, see How are files prepared for the commercial printing of a book?

Frequently asked questions

Where do I find the Amazon KDP and IngramSpark specifications?

In each platform's official help centre, in the sections on interior and cover formatting, and in the tools that generate the cover template from the format, page count and paper. Always consult the official site at the moment of delivery; the rules change.

Is the printer obliged to send the specifications?

There is no formal obligation, but every professional printer has this material and sends it when requested. The designer should ask before finalising the layout and keep the document together with the quote.

What to do if the printer says "send it however you like"?

Apply the market standards — 3 to 5 mm bleed, a safe zone of 5 mm or more, PDF/X with a CMYK profile suited to the paper — and record in writing what was assumed. Then request a proof before releasing the run.

Can I use the same cover file on two platforms?

The design, yes; the file, no. The spine changes according to each platform's paper and formula, and the bleed and safe zones can differ. The cover needs to be rebuilt on each supplier's template.

What is preflight?

It is the automatic and manual check the designer does on the final file before sending it: embedded fonts, image resolution, colour profile, bleed, page size and compliance with the required PDF type. Layout software and Acrobat have their own tools for this.

Related articles

• What is the minimum safety margin a designer should respect for offset and POD printing?
• How are files prepared for the commercial printing of a book?
• When the layout clashes with the printer's technical requirements, what should you do?
• How does the designer adapt a layout for different distribution formats, such as POD and offset?
• How do bleed, margins and endpapers affect the final quality of a printed book?

To understand every aspect of editorial design in one place, read the complete guide: Book designer: the complete guide to book layout and cover design