15th EditionAppendix A: Design and Production—Basic Procedures and Key Terms
The final element in the production of a print publication is binding, which begins with the folding and trimming of the press sheets, or printed sheets, that emerge from the printing press. A press sheet bears printed pages on both sides, each side created from a single plate, and when it is folded in half, and then in half again—continuing until only one page is showing—all the pages fall into proper sequence (see fig. A.11). The folded sheet, called a signature, usually consists of thirty-two pages, but this number may vary depending on the bulk and flexibility of the paper and the size of the offset printing press. When all the signatures have been gathered in the proper order, they are referred to as folded and gathered sheets, or F&Gs. The F&Gs can then be bound in either hardcover or paperback format.
Binding hardcover books typically requires sewing the signatures together, usually by either Smyth sewing or side sewing (see fig. A.12). An alternative method, adhesive binding, involves notching or fraying the folded edges and then applying adhesive to the signatures to hold them together. Smyth- or side-sewn books have a sturdier binding and hold up better over time, but adhesive binding is faster and less costly. In any of these methods, the hardcover case is fashioned by the application of cover material (such as cloth, synthetic fabric, leather, or paper) to boards. The case is then affixed to the body of the book, and a dust jacket may be wrapped around the case.
Journals and paperback books are almost always adhesive-bound through one of three methods: perfect, notch, or burst binding (see fig. A.13). In the perfect-binding method, about an eighth of an inch is mechanically roughened off the spine of the tightly gathered F&Gs, reducing them to a series of separate pages. The roughened spine is then coated with a flexible glue, and a paper cover is wrapped around the pages. In the other two methods, the spine is either scored by a series of notches (notch binding) or perforated (burst binding) and then force-fed with glue. Unlike perfect binding, these methods prevent the loss of part of the back margin and ensure that signatures remain intact, reducing the risk of pages coming loose. For paperbound books of higher quality, the signatures can be sewn and the covers (sometimes with flaps) then affixed, as with adhesive-bound books; this style of binding is known as flexibinding or limpbinding.