A book cover has two separate lives. On a retailer’s page it is a thumbnail, judged in a moment at the size of a postage stamp. At the printer it is a single flat file that has to wrap a physical object, which means it has to be the right size for a spine whose width depends on how many pages the book runs to and what paper it is printed on. The design work and the file work are different jobs, and a cover can be good at one and fail at the other.
This guide gathers our posts on book covers in one place: how the file is put together, what the printers require, what changes between formats, and who owns the result. Each post answers a single question and stands on its own, so start wherever your question sits rather than at the top. We add to the guide as we cover more ground, so it is worth bookmarking.
One caveat: a cover file is the most common thing to be refused at upload, and the reason is almost always dimensional rather than artistic. If a file has been rejected, start with the template and the spine width rather than with the design.
Building the file
- Reading a cover template: what trim, bleed and safe zone mean on the template a printer gives you.
- Spine width: how to work it out from the page count and the paper.
- Bleed: what it is, and why a print cover cannot do without it.
- RGB or CMYK: which color mode to work in, and what shifts between screen and press.
- When KDP refuses the file: the errors it reports, and what each one actually means.
What changes between formats and platforms
- Paperback and hardcover: what has to change when the same book goes to hardcover.
- Ebook covers: the dimensions and file specs an ebook cover needs instead.
- Binding options: what print on demand can and cannot bind.
- Barnes and Noble Press: how to set up a cover file for its print books.
- Matte or glossy: what each finish does to the printed cover.
What goes on it, and who owns it
- Writing a design brief: what to tell a designer so the first draft is close.
- Spine text: whether your book has enough pages to carry any.
- Review quotes: where they go, front or back, and what that does to the design.
- Covers you made yourself: what you own when the artwork came from Canva or a stock library.