How to build the files a printed book is made from: the cover as one continuous sheet, and the interior as one page per book page. Written from the files we actually receive, including the mistakes that get a file sent back.
A cover and an interior. They are measured differently, they fail differently, and mixing up the rules for one with the rules for the other is the single most common reason a file comes back.
01
Covers · casewrap, dust jacket, endpapers
One page, not two: a cover file carries the back, the spine and the front on a single sheet, with bleed all round. Here is how the sheet is measured, where the spine width comes from, and what gets a file sent back.
02
Interiors · margins, text block, page order
One PDF, one page per book page, at trim. The part that decides whether a book is comfortable to read is the text block and its four margins — and the gutter, the one against the binding, is the one people get wrong.
03
AI · page size, panels, layers
Most people now hand the template and their artwork to an AI assistant and ask it to combine them. This is the page to give the assistant. It states the rules a template file has to obey, and how to read the job block we embed in every template.
It prints a large sheet, which is then folded, gathered and trimmed, and every rule in these guides comes from that. Bleed exists because a trimmer cannot cut to a thousandth of an inch, so artwork meant to reach the edge has to run past it. The safety margin exists for the same reason in the other direction: type sitting close to the cut can be shaved. The gutter is generous because the binding takes part of the page and never gives it back.
Work on our templates and none of this needs thinking about. The sheet you download is already the right size, with the trim, the bleed and the safe area drawn on a layer that does not print.
Our templates draw their trim, bleed and safety marks on a PDF layer named Template, so we can hide it and see your artwork alone. Export with layers preserved, or delete that layer before you export.
Flattened guides are ink. If the dashed lines and the dimension callouts end up baked into the artwork, they print on the finished book, and that is a reprint rather than a correction. If you are not sure which your file is, upload it on your order page as it is — a printer reads every file before anything goes on press, and tells you what to change.
Most people now hand the template and their artwork to an AI and ask it to combine them. That works, and these are the rules it has to follow. Attach the template PDF itself — not a screenshot — and paste this:
Follow the instructions at https://www.custombookstudio.com/guides/ai-artwork-setup/ and the job block inside the attached template PDF. Place my artwork on the template without changing the page size, and export with the Template layer hidden.
These guides are for people supplying their own artwork, and plenty do. If you would rather not, our designers and typesetters build print-ready files from a manuscript and a folder of pictures, in the same software the rules above describe.
