The case for a hardback book consists of four pieces of material. Three pieces of cardboard, binder’s board, are cut, two the same size for the front and back cover, and one the same height but only as wide as the spine of the book. The spine board will, unless we are dealing with a square-back book, be much thinner than the front and back boards. The spine on a square-back doesn’t have to bend, so can be the same thickness of board as the side panels. A bit of book cloth, cut to size, is glued up and the bits of board dropped into position. Nowadays, rather than a woven fabric which will be stronger and longer-lasting, we often use a paper product for covering material. It’s cheaper. The edges of the cloth are turned over and stuck over the edges of the board. The cases are transferred to the stamping department where the title etc. will be foil-stamped onto the spine, using pressure and heat. And lo and behold we are ready to stick the end-papered book block into the case in the process called forwarding and building-in.

A case (3 bits of grey board and one bit of black cloth) shown with a set of sheets, folded and gathered but not yet sewn.

A stamping die

Nowadays the cover is often a three-piece case which adds an extra step before case making where a wide band for the spine (in theory a stronger cloth material than the paper being used on the sides, but increasingly just another bit of paper) is glued to the two panels for the sides before we get to the point where the boards can be stuck to it.

A three-pice case, all made of paper. This one has deckle edges.

The three-piece case originated as a cost saving wheeze (what else is new?) by book publishers. If you put paper on the sides of the book you’d cut down on the use of more expensive book cloth. Leaving cloth on the spine would provide strength for what’s the most vulnerable bit of the binding, the top edge of the spine where one tends to use a finger to pull a volume out of a shelf of books. Now we’ve pretty much abandoned the use of  book cloth in trade publishing altogether, there’s nothing to save by using a three-piece case. But now it’s become a “look”: we, the public, are believed to expect a trade book to look like this, so publishers keep on doing it. This despite the fact that if you use the same material on front and spine a three piece case will actually increase your costs — you’ve got to cut and assemble the case cover out of three pieces. I used to estimate that the break-even on a three-piece case (the point at which the unit cost becomes less, when the material savings balanced out the extra makeready) was around 1,500 copies: not a large number for a trade book of course.