Leather is synonymous with tradition in fine book publishing and collecting. Publishers such as the Easton Press, and until recently, the Franklin Press, have made it their business to continue the historic practice of matching a fine leather binding to the great works of literature.
Leather has a long history in the Western bookbinding tradition. Among the oldest surviving books in the world is the Nag Hammadi Library, consisting of 13 Coptic papyrus codices bound in leather, dating from the 3rd and 4th centuries. The origins of leather as a method of holding together the pages of a book are most likely in practicality. In some of the earliest forms of Western bookbinding, a book would consist of loose pages covered by wooden boards. Those boards served to protect the pages within and the addition of a hinge of leather cords made this arrangement easier to use. In time, the leather hinges expanded to become a covering over the entire wooden surface area. The leather surfaces naturally invited decoration, growing over time into the expression of the craft of bookbinding we are familiar with today.
The single greatest reason for the perseverance of leather in bookbinding is likely because of its practicality. Properly prepared animal skin is enormously sturdy, resists changes in temperature, humidity and a host of insults that time and use might contribute, remaining flexible and intact long after other materials have succumbed to age and wear. To this day, the British Parliament records its laws on vellum, a traditional writing surface of thin animal skin. Despite the cost of this thoroughly unmodern practice, the British government has resisted cost-cutting proposals because of vellum's durability. Acid-free, archival paper lasts around 200 years, while vellum has a predicted lifespan of 5,000 years.
Aside from its durability, animal skin has remained an abundant material. Domestic animal husbandry produces a ready supply of hides, and any animal which has been domestically raised has been used in bookbinding at some point.
Leather is not the only material that has been used in bookbinding, but it is definitely one of the most common. Within that commonality, though, resides a great wealth of variety in both the types of skin used as well as the methods of preparation and decoration.
Until the early 19th century, books were published either in a binding provided by the bookseller or in temporary bindings to be later replaced by a professional binder. The permanent binding was dictated by the tastes of the book's owner and the skill of the binder. As a result, there is not necessarily one binding associated with an antiquarian book. While many historic bindings tend to share similar traits and motifs, a great deal of individual artisanship also comes into play. The most accomplished bookbinders would sign their work by adding a small stamp with their name, usually added subtly to the inside edge of the head of the spine. Signed bindings tend to be especially desirable in the collectors' market.
Varieties of leather:
Vellum: A very fine parchment derived from a young calf, kid or lamb. Vellum is exceedingly smooth grained and can tend to shrink, allowing it to become a very finely fitted, tight covering when stretched over board covers.
Calfskin: Top grained leather from a calf. This material is one of the most common book coverings, and one of the most widely disparate. Calfskin is smooth and a light brown, but it is frequently textured and dyed to create a very different final product.
Morocco: Goatskin typically characterized by a fine, pebble grain, and prized for the way it exhibits gilt when applied. This form of leather comes from Morocco originally, hence the name.
Roan: Sheepskin dyed and textured to resemble Morocco as a cheaper substitute for that more desirable material.
Skiver: A relatively cheap form of outer grain sheep (or possibly goat) skin. Skiver is not typically valued as a bookbinding material, but it is frequently used for spine labels.
Bonded leather: This is only barely leather. Bonded leather is formed from leather fibers which are affixed to another material, such as polyurethane. Bonded leather is not a traditional method of bookbinding, but it has become a standard practice to create the appearance of a leather binding cheaply.
Varieties of leather bindings:
Limp binding: Leather is often stretched over hard boards (either cardboard or wooden), but leather can also be left flexible, covering the front, back, and spine of the book. When extended over the fore edge to protect the textblock, it forms what’s called a yapp style binding.
Limp bound leather originates in medieval traditions, but more recently limp bound suede bindings were a hallmark of the Arts and Crafts movement bookbinder, Roycroft Press.
Books may be entirely bound in leather, or leather might be paired with another covering material.
Quarter bound: The spine is leather covered, but the front and rear boards are covered with a different material.
Half bound: The spine and the corners of both the front and back boards are covered with leather, while the remaining portions of the front and back boards are covered with a different material.
Three quarter bound: The spine and part of the front and rear boards are covered in leather, as are the corners of both the front and back boards. Similar to half bound, with a greater amount of the spine and corners bound in leather, resulting in approximately ¾ of the total outside of the book being leather.
In all of the partial leather bindings, the leather is often paired with a complementary material, such as a pebble-grained cloth, or a decorative contrasting material like marbled paper.
Leather is a perfect template for tooling and embossing. Binders use many of the same techniques and tools as other leather workers, but binding has a long tradition, and a vocabulary unique to its uses.
Textures and lines:
Blind tooling: A decorative engraving or carving which is left uncolored, matching the surrounding material.
Gold tooling: The application of gold paint to carving and tooling.
Dentelle: A border running along the outside edges of a cover.
Embossed: Leather with a pattern which has been pressed into it.
Pebbled leather: A pattern of small, regular bumps pressed into the smooth calfskin, possibly to emulate the appearance of morocco.
Colors and patterns:
Leather can be dyed to any color. Both calfskin and morocco are usually dyed. A special variant, sometimes called law, is a very lightly colored or uncolored leather, so named as it was often employed for binding law books.
In addition to coloring the leather, a number of other methods of changing the appearance of the leather arose over time:
Marbled calf: An acidic solution is flowed over the surface of the leather, creating the appearance of marble.
Mottled calf: An acidic solution or dye is sponged or dabbed onto the leather creating a varied pattern.
Tree calf: Dating from approximately 1775, is created when an acidic compound is dripped from the top to the bottom edges of the front and rear boards, creating the appearance of the trunk and branches of a tree.
Rough calf: The interior side of the leather surface is turned outward.
Polished calf: Possibly the most common presentation of a calf binding, wherein the leather is polished to a fine, smooth finish.
Some less common varieties of leather:
A number of one-off, bespoke bindings have been produced using exotic animals, including leopard, lion and other fur-covered skins. These ostentatious bindings are often combined with books on African exploration or hunting.
Sealskin: In the mid to late 1960's, Thomas Nelson publishers offered an exotic edition of their Scofield study bible, bound in sealskin. Copies of this uncommon edition sometimes show up on the used and rare book market.
Anthropodermic bibliopegy: This clinical Latinate term hides a dark tradition. These are books bound in human skin. This is, for obvious reasons, a very uncommon method of bookbinding, but it achieved some degree of popularity in the 17th century. Most frequently, this type of binding was found in 17th-century anatomy texts where the covering material was somewhat suitable to the material contained within.