Dust jackets, and the extra geometry they need
A dust jacket is not a cover. It is a separate printed sheet, wrapped around a book that is already bound and already has a cover underneath it. Nothing holds it on but two flaps tucked inside the boards, and a reader can take it off in a second.
That explains every awkward thing about designing one: a jacket is wider than the book it wraps, so it has folds, and every fold is a place where artwork turns a corner and stops being visible.
Five panels and four folds
Laid flat, a jacket reads left to right: back flap, back panel, spine, front panel, front flap. Four folds separate them, and only three of the five panels face a browsing reader at once.
The panel that surprises people is the flap. Flap width is set by the printer, not by you, and measured off that company's own template — there is no universal figure and no formula worth trusting. Get the template for the exact trim, page count and printer before you draw anything. The printer's template, and how to read it covers what the layers in that file mean.
The flaps need copy, and less of it than you think
The convention is settled, and nothing is gained by fighting it.
- Front flap — the blurb. The selling copy that would go on the back of a paperback, usually a little shorter. If it overruns, traditional books break it with "continued on back flap" rather than shrinking the type. Write it to fit instead; How to write a blurb that sells the book is the drafting method.
- Front flap, top corner — the price. A printed price commits you. If yours may move, leave the corner clear.
- Back flap — the author. A short biography in the third person and a photograph if you have a usable one. See The author photo, and where it belongs.
- Back flap, foot — the imprint. Publisher name or mark, matching the spine and the title page.
A flap is narrow. Set the type at a size you would read in the book itself, then cut words until it fits — not the other way around.
That leaves the back panel for review quotes, a series list, or nothing at all, and for the barcode, which still owns its 2 × 1.2 inch corner. What goes on the back cover applies to a jacket's back panel as it does to a paperback's.
The front panel starts at the fold
This is the error that costs people a reprint.
The front panel does not begin at the edge of the sheet. It begins at the fold between the front flap and the front panel, and everything to the left of that fold wraps around the fore-edge of the board and disappears inside the book.
So artwork placed from the sheet edge lands in the wrong place, and a title centered on what looked like the front is not centered on what the reader sees. Position from the fold, keep the important part of the image and all of your type well inside the panel, and treat the first quarter-inch past each fold as gone. The same runs the other way at the spine folds: art that crosses onto the spine is bent around the hinge, not flat on the face.
In the Cover Maker. Choose dust jacket as the binding and the flaps, folds and panel widths are built from the printer's own geometry, with live trim, bleed and safe-area guides drawn across the whole sheet and the spine computed from the real page count. Start a book → · about the Cover Maker
Bleed at the outer edges, not at the folds
Bleed exists because a trimming blade is not perfect. It applies where the sheet is cut: the top, the bottom, and the far outer edge of each flap. Allow 0.125 in of extra artwork past the trim on those edges, and keep anything that matters about 0.25 in inside it.
A fold is not a cut. There is no bleed at a flap fold or at either spine fold — the image simply continues across it. What a fold needs is tolerance, because the folding machine has its own variation, which is why type and logos should never sit tight against one.
There is still a book under it
A jacketed book is a case-bound book with a wrapper, so you are producing two cover files: the jacket, and the case beneath it.
Most publishers do not put the full artwork on both. The usual choices for the case are a flat color with the title, author and imprint on the spine, or a plain cloth-look ground with nothing on the face. The reader sees it when the jacket comes off, and a careless case is noticed by the readers who care most.
Build the case from its own template — its geometry is board wrap and turn-in, not flaps — rather than trimming the jacket down.
Should your first book have one?
Probably not. A jacket adds a second cover file, two panels of copy that have to be written, and manufacturing cost on top of a hardcover that already costs more than the paperback. That is a lot of work for an edition whose buyers, as covered in Paperback, hardcover, or both, are mostly readers who already know your name.
Make one when there is a reason: an illustrated or gift book where the object is the product, a nonfiction title aimed at libraries, or a special edition for an audience that is already asking. Otherwise a case laminate hardcover gives you the same durability and shelf presence, with one file to get right instead of two.
Make yours
Everything here is built into the tools, and they are free to use: name your book, bring your manuscript or your artwork, and work as long as you like. You only pay when you want the files without the preview watermark.
Next: Paperback, hardcover, dust jacket: what changes · More: Paperback, hardcover, or both · Bleed and safe area, explained once · What goes on the back cover