Saddle Stitch, Coil
or Perfect Binding?

Saddle stitch: fast, flat-opening, locked to multiples of four

Folded sheets are nested inside one another over a saddle, stapled through the spine fold, and trimmed on three sides in one pass. It is generally the least expensive binding, and it opens close to flat. Two things are structural rather than optional: the page count has to be a multiple of four, because every folded sheet contributes four pages, and there is a practical thickness ceiling. As a rule of thumb in the trade, saddle stitching suits booklets from as few as 8 pages up into roughly the 60-to-90-page range, though that ceiling moves with how heavy the stock is — a book on heavier paper hits its practical limit sooner than the same page count on a lighter sheet. Past that ceiling, the inner pages start to push outward (called creep) enough that trimming visibly narrows their outer margin, and the spine gets too thick to lie down properly.

Coil binding: any page count, dead flat, no printed spine

A continuous plastic (or wire) coil winds through a row of holes punched down the spine. The mechanical advantage is real: a coil-bound book lies flat on a table and folds all the way back on itself, which is why manuals, workbooks, cookbooks and wall calendars are usually coiled and catalogs generally are not — anything that needs to stay open on its own while somebody’s hands are busy wants a coil. Coil is also not locked to multiples of four the way saddle stitch is, and handles a much wider range of thicknesses. As commonly stocked in the trade, coil comes in a range of diameters and colors sized to a document’s thickness; what looks right on a 40-page booklet is not stiff enough to hold a 300-page manual. What coil gives up is a printed spine — there is no flat panel for a title, since the binding itself is a series of loops rather than a solid edge.

Perfect binding: a flat glued spine, and a minimum thickness to work with

Perfect binding glues the gathered pages to a wraparound cover at a flat spine, using a hot-melt or PUR adhesive — how most paperback books and thicker perfect-bound magazines are put together. The flat spine is the whole point: it is what lets a title print along the edge of a shelved book. As a rule of thumb in the trade, perfect binding generally needs a minimum thickness for the adhesive to grip a stable spine, commonly cited as somewhere in the neighborhood of 40 or more pages; thinner than that, the glue has too little surface and too little flex to hold reliably. A close relative is thermal binding, which glues a similar flat spine through a different heat-activated process and produces a comparable look. Not every bindery runs every one of these three methods — ask what a given shop actually has on its floor before you design around one; see bindery for what runs here.

Choosing between the three

• Needs to lie flat while somebody works from it, or the page count varies? Coil.
• Ordinary booklet, catalog or program, moderate page count, cost matters? Saddle stitch, in multiples of four.
• Wants to look like a real book on a shelf, with a printed spine, and has real thickness to work with? Perfect or thermal binding.

All three interact with prepress before they interact with the bindery: page count, panel order and imposition are set before plates are made, not discovered afterward — see the imposition note in prepress. And a hard-copy proof of a bound piece is the only reliable way to see how it will actually open and lie; see what to check on a print proof.