Why some books are still sewn

Most short-run books, reports and catalogues today are perfect bound: the pages are trimmed at the spine and glued into a cover. That works well for many jobs. But open a well-made hardcover photography book, a reference manual or a family history printed to last, and you will usually find thread at the centre of each section. Section sewing is slower and more involved than gluing, and it remains the method of choice when a book has to open flat, take years of handling and keep every page in place.

This article explains how a section-sewn hardcover is built, step by step, so you can specify one with confidence and understand what you are paying for. If you are still choosing between binding styles, our comparison of binding methods covers saddle stitch, perfect binding, wire-o and case binding side by side.

Step one: printing and folding sections

A sewn book starts as large press sheets, each printed with many pages in a planned arrangement. After printing, each sheet is folded down into a section, also called a signature. Depending on the paper and page size, a section typically holds 8, 16 or 32 pages.

The section count matters for the page count of the book. Your total should divide neatly into sections, or the printer will need to add a smaller section somewhere, which costs extra handling. Ask early which section size the printer plans to use, especially if you are working to a fixed number of pages.

Paper and grain

For a sewn book, the paper grain should run parallel to the spine. Pages with grain running the right way turn easily and lie flat. Pages with grain running across the spine fight the binding, ripple along the fold and make the book stiff to open. A good printer plans the imposition around this, but if you are supplying your own paper or choosing an unusual size, confirm it.

Step two: gathering and sewing

The folded sections are gathered in order to form the book block. A collation mark, a small printed block on the spine fold of each section, steps down from one section to the next. When the sections are stacked correctly, the marks form a neat diagonal line. A missing or doubled section breaks the line and is spotted at a glance.

The book block is then sewn. A sewing machine passes needles and thread through the fold of each section, linking it to the one before. The thread runs along the inside of each fold, so every page is held by thread as well as glue. This is often called Smyth sewing after the type of machine that made it common.

Why thread makes a difference

• Lay-flat opening. Because each section hinges on its own fold, the book opens fully without pressure on the spine.
• Durability. Pages cannot drop out the way they can from a poorly glued spine.
• Paper tolerance. Coated and heavy papers, which can be difficult for glue alone, are held mechanically by the thread.

Section sewing is also used inside some softcover books. A sewn and glued softcover gets most of the strength of thread at a lower cost than a hardcover. If you are binding a softcover with glue only, our guide to PUR or EVA glue for perfect binding explains how to choose an adhesive that holds.

Step three: endpapers

Endpapers are the folded sheets that join the book block to the cover. One is attached to the front of the block and one to the back, usually with a narrow strip of glue along the fold. Half of each endpaper is later glued to the inside of the cover board, and the other half becomes the first free page of the book.

Endpapers can be plain, coloured or printed. Printed endpapers are a popular way to add a map, a pattern or a full-bleed photo. They are on a stronger paper than the text pages because they carry the weight of the block at the hinge.

Step four: finishing the spine

Once sewn, the block is pressed, glued along the spine and trimmed on the other three sides. Then the spine is shaped.

Flat or rounded

A flat spine gives a modern, square look and suits thinner books. A rounded spine, formed by rounding and backing the block, curves the spine outward and creates small shoulders for the boards to sit against. Rounding helps thicker books keep their shape over time and stops the fore-edge from sinking into a concave curve.

Lining, mull and headbands

A cloth lining called mull or super is glued over the spine and extends onto the endpapers, adding strength at the hinge. Headbands, small strips of striped fabric at the top and bottom of the spine, are mostly decorative today but give a finished look and cover the ends of the sections.

Step five: making the case

The hard cover, or case, is made separately from the book block. Two boards of rigid greyboard and a narrower spine piece are laid onto the cover material with gaps between them for the hinges. The cover material is wrapped around the edges and glued on the inside, a step called the turn-in.

Common cover materials include:

A printed paper cover is usually laminated so it survives handling. Our guide to gloss, matte, soft-touch and anti-scuff lamination explains how each finish wears. Cloth covers are often finished with a foil-stamped title on the spine and front board, and a printed dust jacket can be added on top.

Step six: casing in

Finally, the book block is placed into the case. The outer halves of the endpapers are glued to the inside of the boards, the book is pressed, and a groove is formed along each hinge so the cover opens easily. The book then needs time under pressure for the glue to set before it is packed. Rushing this step can lead to warped boards.

What to tell your printer when you ask for a quote

• Finished size, page count and text paper.
• Sewn or glued block, and flat or rounded spine.
• Cover material, finish and any foil or embossing.
• Plain or printed endpapers, and headband colour if you have a preference.
• Dust jacket or not, and quantity.

Lead times for sewn hardcovers are longer than for perfect-bound books because of the extra steps and drying time. Plan for that when you set a launch date.

Sewn hardcover production at our print shop

We produce section-sewn books in both hardcover and softcover, from short runs for families and archives to longer runs for publishers and organisations. Our team checks grain direction, section planning and spine width against your page count before the job goes to press, so the book block and case fit together properly. Have a look at our brochure and booklet printing services, or contact us with your specification for a quote and a production schedule.