One canvas, three panels

A wraparound cover is laid out left to right as back cover, spine, front cover, with bleed on all four outer edges. The tool computes the spine from page count and stock (see the spine calculator), adds two trim widths and two bleeds, and reports the total size in your chosen unit and in pixels at your resolution. Each guide position is listed in inches, pixels and PDF points, measured from the left edge, so you can drop them straight into your canvas as guides. If your printer has already quoted a spine width, choose that option under paper stock and the cover is built to it.

Saddle-stitched covers

Stapled books have no spine, so switch the binding to saddle stitch and the cover collapses to two trims side by side. Many printers still want the cover delivered as one spread so the art can run across the fold.