Bookbinding



Bookbinding is the process of physically assembling a book from a number of folded or unfolded sheets of paper or other material. It usually involves attaching a book cover to the resulting text-block.

Origins of the book
There is no way to be certain where book crafting originated; it was an evolving art encompassing techniques from a variety of cultures and civilizations.

The craft of bookbinding probably originated in India, where religious sutras were copied on to palm leaves (cut into two, lengthwise) with a metal stylus. The leaf was then dried and rubbed with ink, which would form a stain in the wound. The finished leaves were given numbers, and two long twines were threaded through each end through wooden boards, making a palm-leaf book. When the book was closed, the excess twine would be wrapped around the boards to protect the manuscript leaves. Buddhist monks took the idea through Persia, Afghanistan, and Iran, to China in the first century BC.

Similar techniques can also be found in ancient Egypt where priestly texts were compiled on scrolls and books of papyrus. Another version of bookmaking can be seen through the ancient Mayan codex; only four are known to have survived the Spanish invasion of Latin America.

Writers in the Hellenistic-Roman culture wrote longer texts as scrolls; these were stored in shelving with small cubbyholes, similar to a modern winerack. The word volume, from the Latin word volvere ("to roll"), comes from these scrolls. Court records and notes were written on wax tablets, while important documents were written on papyrus or parchment. The modern English word book comes from the Proto-Germanic *bokiz, referring to the beechwood on which early written works were recorded.

The book was not needed in ancient times, as many early Greek texts—scrolls—were thirty pages long, which were customarily folded accordion-fashion to fit into the hand. Roman works were often longer, running to hundreds of pages. The Greeks used to comically call their books tome, meaning "to cut". The Egyptian Book of the Dead was a massive 200 pages long and was used in funerary services for the deceased. Torah scrolls, editions of the Jewish holy book, were—and still are—also held in special holders when read.

Scrolls can be rolled in one of two ways. The first method is to wrap the scroll around a single core, similar to a modern roll of paper towels. While simple to construct, a single core scroll has a major disadvantage: in order to read text at the end of the scroll, the entire scroll must be unwound. This is partially overcome in the second method, which is to wrap the scroll around two cores, as in a Torah. With a double scroll, the text can be accessed from both beginning and end, and the portions of the scroll not being read can remain wound. This still leaves the scroll a sequential-access medium: to reach a given page, one generally has to unroll and re-roll many other pages.

Early book formats
In addition to the scroll, wax tablets were commonly used in Antiquity as a writing surface. Diptychs and later polyptych formats were often hinged together along one edge, analogous to the spine of modern books, as well as a folding concertina format. Such a set of simple wooden boards sewn together was called by the Romans a codex (pl. codices)—from the Latin word caudex, meaning 'the trunk' of a tree, around the first century AD. Two ancient polyptychs, a pentaptych and octoptych, excavated at Herculaneum employed a unique connecting system that presages later sewing on thongs or cords.

At the turn of the first century, a kind of folded parchment notebook called pugillares membranei in Latin, became commonly used for writing in the Roman Empire. This term was used by both the pagan poet Martial and Christian apostle Paul the Apostle. Martial used the term with reference to gifts of literature exchanged by Romans during the festival of Saturnalia. According to T. C. Skeat, "…in at least three cases and probably in all, in the form of codices" and he theorized that this form of notebook was invented in Rome and then "…must have spread rapidly to the Near East…" In his discussion of one of the earliest pagan parchment codices to survive from Oxyrhynchus in Egypt, Eric Turner seems to challenge Skeat's notion when stating "…its mere existence is evidence that this book form had a prehistory" and that "early experiments with this book form may well have taken place outside of Egypt."

Early intact codices were discovered at Nag Hammadi in Egypt. Consisting of primarily Gnostic texts in Coptic, the books were mostly written on papyrus, and while many are single-quire, a few are multi-quire. Codices were a significant improvement over papyrus or vellum scrolls in that they were easier to handle. However, despite allowing writing on both sides of the leaves, they were still foliated—numbered on the leaves, like the Indian books. The idea spread quickly through the early churches, and the word Bible comes from the town where the Byzantine monks established their first scriptorium, Byblos, in modern Lebanon. The idea of numbering each side of the page—Latin pagina, "to fasten"—appeared when the text of the individual testaments of the Bible were combined and text had to be searched through more quickly. This book format became the preferred way of preserving manuscript or printed material.

History of bookbinding
Western books from the fifth century onwards were bound between hard covers, with pages made from parchment folded and sewn on to strong cords or ligaments that were attached to wooden boards and covered with leather. Since early books were exclusively handwritten on handmade materials, sizes and styles varied considerably, and there was no standard of uniformity. Early and medieval codices were bound with flat spines, and it was not until the fifteenth century that books began to have the rounded spines associated with hardcovers today. Because the vellum of early books would react to humidity by swelling, causing the book to take on a characteristic wedge shape, the wooden covers of medieval books were often secured with straps or clasps. These straps, along with metal bosses on the book's covers to keep it raised off the surface that it rests on, are collectively known as furniture.

The earliest surviving European bookbinding is the St Cuthbert Gospel of about 700, in red goatskin, now in the British Library, whose decoration includes raised patterns and coloured tooled designs. Very grand manuscripts for liturgical rather than library use had covers in metalwork called treasure bindings, often studded with gems and incorporating ivory relief panels or enamel elements. Very few of these have survived intact, as they have been broken up for their precious materials, but a fair number of the ivory panels have survived, as they were hard to recycle; the divided panels from the Codex Aureus of Lorsch are among the most notable. The 8th century Vienna Coronation Gospels were given a new gold relief cover in about 1500, and the Lindau Gospels (now Morgan Library, New York) have their original cover from around 800.

Luxury medieval books for the library had leather covers decorated, often all over, with tooling (incised lines or patterns), blind stamps, and often small metal pieces of furniture. Medieval stamps showed animals and figures as well as the vegetal and geometric designs that would later dominate book cover decoration. Until the end of the period books were not usually stood up on shelves in the modern way. The most functional books were bound in plain white vellum over boards, and had a brief title hand-written on the spine. Techniques for fixing gold leaf under the tooling and stamps were imported from the Islamic world in the 15th century, and thereafter the gold-tooled leather binding has remained the conventional choice for high quality bindings for collectors, though cheaper bindings that only used gold for the title on the spine, or not at all, were always more common. Although the arrival of the printed book vastly increased the number of books produced in Europe, it did not in itself change the various styles of binding used, except that vellum became much less used.



Introduction of paper
Cai Lun (ca. 50 AD – 121) improved the first significant improvement and standardization of papermaking by adding essential new materials into its composition.

In the 8th century Arabs learned the arts of papermaking from the Chinese and were then the first to bind paper into books at the start of the Islamic Golden Age. Particular skills were developed for Arabic calligraphy, miniatures and bookbinding. The people who worked in making books were called Warraqin or paper professionals. The Arabs made books lighter—sewn with silk and bound with leather covered paste boards, they had a flap that wrapped the book up when not in use. As paper was less reactive to humidity, the heavy boards were not needed. The production of books became a real industry and cities like Marrakech, Morocco, had a street named Kutubiyyin or book sellers, which contained more than 100 bookshops in the 12th century; the famous Koutoubia Mosque is named so because of its location on this street. Because the Qur'an itself was considered a sacred object, in order to beautify the book containing the holy scripture, a culture of calligraphy and lavish bookbinding developed.



Development
With the arrival (from the East) of rag paper manufacturing in Europe in the late Middle Ages and the use of the printing press beginning in the mid-15th century, bookbinding began to standardize somewhat, but page sizes still varied considerably.

With printing, the books became more accessible and were stored on their side on long shelves for the first time. Clasps were removed, and titles were added to the spine. The reduced cost of books facilitated cheap lightweight Bibles, made from tissue-thin oxford paper, with floppy covers, that resembled the early Arabic Qurans, enabling missionaries to take portable books with them around the world, and modern wood glues enabled paperback covers to be added to simple glue bindings.

Historical forms of binding
Historical forms of binding include the following:
 * Coptic binding
 * Ethiopian binding
 * Long-stitch bookbinding
 * Islamic bookcover with a distinctive flap on the back cover that wraps around to the front when the book is closed.
 * Wooden board
 * Limp vellum
 * Calf-binding ("leather-bound")
 * Paper case
 * In-board cloth
 * Cased cloth binding
 * Bradel Binding
 * Secret Belgian binding
 * Traditional Chinese bookbinding and Japanese stab binding
 * Girdle binding

Some books have even been bound in human skin, a practice known as anthropodermic bibliopegy.

Modern commercial binding
There are various commercial techniques in use today. Today, most commercially produced books belong to one of four categories:

Hardcover binding
A hardcover, hardbound book has rigid covers and is stitched in the spine. Looking from the top of the spine, the book can be seen to consist of a number of signatures bound together. When the book is opened in the middle of a signature, the binding threads are visible. Signatures of hardcover books are typically octavo (a single sheet folded three times), though they may also be folio, quarto, or 16mo (see Book size). Unusually large and heavy books are sometimes bound with wire.

Until the mid-20th century, covers of mass-produced books were laid with cloth, but from that period onwards, most publishers adopted clothette, a kind of textured paper which vaguely resembles cloth but is easily differentiated on close inspection. Most cloth-bound books are now half-and-half covers with cloth covering only the spine. In that case, the cover has a paper overlap. The covers of modern hardback books are made of thick cardboard.

Some books that appeared in the mid-20th century signature-bound appear in reprinted editions in glued-together editions. Copies of such books stitched together in their original format are often difficult to find, and are much sought after for both aesthetic and practical reasons.

A variation of the hardcover which is more durable is the calf-binding, where the cover is either half or fully clad in leather, usually from a calf. This is also called full-bound or, simply, leather bound.

Library binding refers to the hardcover binding of serials and paperback books intended for the rigors of library use. Though many publishers have started to provide "library binding" editions, many libraries elect to purchase paperbacks and have them rebound as hardcover books, resulting in longer life for the material.

Methods of hardcover binding
There are a number of methods used to bind hardcover books, from them:
 * 1) Case binding is the most common type of hardcover binding for books. The pages are arranged in signatures and glued together into a "textblock.". The textblock is then attached to the cover or "case" which is made of cardboard covered with paper, cloth, vinyl or leather. This is also known as perfect binding, cloth binding, or edition binding.
 * 2) Oversewing, where the signatures of the book start off as loose pages which are then clamped together. Small vertical holes are punched through the far left-hand edge of each signature, and then the signatures are sewn together with lock-stitches to form the text block. Oversewing is a very strong method of binding and can be done on books up to five inches thick. However, the margins of oversewn books are reduced and the pages will not lie flat when opened.
 * 3) Sewing through the fold (also called Smyth sewn), where the signatures of the book are folded and stitched through the fold. The signatures are then sewn or glued together at the spine to form a text block. In contrast to oversewing, through-the-fold books have wide margins and can open completely flat. However, the text block of a sewn-through-the-fold book is not very secure, which can cause some signatures to come loose over time. Many varieties of sewing stitches exist, from basic links to complex decorative stitches. While Western books are generally sewn through holes punched along the fold, some Asian bindings, such as the Retchoso or Butterfly Stitch of Japan, use small slits instead of punched holes.
 * 4) Double-fan adhesive binding starts off with two signatures of loose pages, which are run over a roller—"fanning" the pages—to apply a thin layer of glue to each page edge. Then the two signatures are perfectly aligned to form a text block, and glue edges of the text block are attached to a piece of cloth lining to form the spine. Double-fan adhesive bound books can open completely flat and have a wide margin. However, certain types of paper do not hold adhesive well, and, with wear and tear, the pages can come loose.

Punch and bind
Different types of the punch and bind binding include:
 * 1) Double wire, twin loop, or Wire-O binding is a type of binding that is used for books that will be viewed or read in an office or home type environment. The binding involves the use of a "C" shaped wire spine that is squeezed into a round shape using a wire closing device. Double wire binding allows books to have smooth crossover and is affordable in many colors. This binding is great for annual reports, owners manuals and software manuals. Wire bound books are made of individual sheets, each punched with a line of round or square holes on the binding edge. This type of binding uses either a 3:1 pitch hole pattern with three holes per inch or a 2:1 pitch hole pattern with two holes per inch. The three to one hole pattern is used for smaller books that are up to 9/16" in diameter while the 2:1 pattern is normally used for thicker books as the holes are slightly bigger to accommodate slightly thicker, stronger wire. Once punched, the back cover is then placed on to the front cover ready for the wire binding elements (double loop wire) to be inserted. The wire is then placed through the holes. The next step involves the binder holding the book by its pages and inserting the wire into a "closer" which is basically a vise that crimps the wire closed and into its round shape. The back page can then be turned back to its correct position, thus hiding the spine of the book.
 * 2) Comb binding uses a 9/16" pitch rectangular hole pattern punched near the bound edge. A curled plastic "comb" is fed through the slits to hold the sheets together. Comb binding allows a book to be disassembled and reassembled by hand without damage. Comb supplies are typically available in a wide range of colors and diameters. The supplies themselves can be re-used or recycled. In the United States, comb binding is often referred to as 19-ring binding because it uses a total of 19 holes along the 11-inch side of a sheet of paper.
 * 3) VeloBind is used to permanently rivet pages together using a plastic strip on the front and back of the document. Sheets for the document are punched with a line of holes near the bound edge. A series of pins attached to a plastic strip called a Comb feeds through the holes to the other side and then goes through another plastic strip called the receiving strip. The excess portion of the pins is cut off and the plastic heat-sealed to create a relatively flat bind method. VeloBind provides a more permanent bind than comb-binding, but is primarily used for business and legal presentations and small publications.
 * 4) Spiral binding is the most economical form of mechanical binding when using plastic or metal. It is commonly used for atlases and other publications where it is necessary or desirable to be able to open the publication back on itself without breaking the spine. There are several types but basically it is made by punching holes along the entire length of the spine of the page and winding a wire helix (like a spring) through the holes to provide a fully flexible hinge at the spine. Spiral coil binding uses a number of different hole patterns for binding documents. The most common hole pattern used with this style is 4:1 pitch (4 holes per inch). However, spiral coil spines are also available for use with 3:1 pitch, 5:1 pitch and 0.400-hole patterns.
 * 5) Proclick (GBC) is a relatively new binding style that was originally designed for use with a 3:1 pitch wire binding hole pattern. This type of binding uses an element that snaps shut and can be easily opened for editing purposes. The editing abilities of this style make it popular with direct sales organizations and mobile offices.  Proclick is manufactured exclusively by the General Binding Corporation.
 * 6) ZipBind is also manufactured by the General Binding Corporation and offers easy editing. However, the binding spines for this style are designed to work with the 9/16" plastic comb binding hole pattern. Like Proclick, Zipbind spines can easily be opened and closed without the need for a binding machine. Thus the addition and deletion of pages is a simple process provided that the pages have already been punched.

Thermally activated binding
Some of the different types of thermally activated binding include:
 * 1) Perfect binding is often used, and gives a result similar to paperback books. National Geographic is one example of this type. Paperback or soft cover books are also normally bound using perfect binding. They usually consist of various sections with a cover made from heavier paper, glued together at the spine with a strong flexible glue. The sections are rough-cut in the back to make them absorb the hot glue. The other three sides are then face trimmed. This is what allows the magazine or paperback book to be opened. Mass market paperbacks (pulp paperbacks) are small (16mo size), cheaply made with each sheet fully cut and glued at the spine; these are likely to fall apart or lose sheets after much handling or several years. Trade paperbacks are more sturdily made, with traditional gatherings or sections of bifolios, usually larger, and more expensive.  The difference between the two can usually easily be seen by looking for the sections in the top or bottom sides of the book.
 * 2) Thermal binding uses a one piece cover with glue down the spine to quickly and easily bind documents without the need for punching. Individuals usually purchase "thermal covers" or "therm-a-bind covers" which are usually made to fit a standard size sheet of paper and come with a glue channel down the spine. The paper is placed in the cover, heated in a machine (basically a griddle), and when the glue cools, it adheres the paper to the spine. Thermal glue strips can also be purchased separately for individuals that wish to use customized/original covers. However, creating documents using thermal binding glue strips can be a tedious process which requires a scoring device and a large format printer.
 * 3) A cardboard article looks like a hardbound book at first sight, but it is really a paperback with hard covers. Many books that are sold as hardcover are actually of this type. The Modern Library series is an example. This type of document is usually bound with thermal adhesive glue using a perfect binding machine.
 * 4) Tape binding refers to a system that wraps and glues a piece of tape around the base of the document. A tape binding machine such as the Powis Parker Fastback or Standard Accubind system will usually be used to complete the binding process and to activate the thermal adhesive on the glue strip. However, some users also refer to Tape Binding as the process of adding a colored tape to the edge of a mechanically fastened (stapled or stitched) document.
 * 5) Unibind is a variety of thermal binding that uses a special steel channel with resin rather than glue inside of it to give it a more sturdy bind to hold the pages in place. Unibind can be used to bind soft covered documents with a look that is similar to perfect binding. It can also be used for binding hardcover books and photo books. Like Thermal Binding, unibind usually requires you to purchase a one piece coverset to bind your documents. However, Unibind also offers SteelBack spines that allow you to use your own covers in the binding process. The majority of Unibinds covers can be printed on as well to give documents a unique finish. (Unibind is also the name of an International binding company)

Stitched or sewn binding
Types of stitched or sewn bindings:
 * 1) A sewn book is constructed in the same way as a hardbound book, except that it lacks the hard covers. The binding is as durable as that of a hardbound book.
 * 2) Stapling through the centerfold, also called saddle-stitching, joins a set of nested folios into a single magazine issue; most American comic books are well-known examples of this type.
 * 3) Magazines are considered more ephemeral than books, and less durable means of binding them are usual. In general, the cover papers of magazines will be the same as the inner pages (self-cover) or only slightly heavier (plus cover). Most magazines are stapled or saddle-stitched; however, some are bound with perfect binding and use thermally activated adhesive.

Modern hand binding
Modern bookbinding by hand can be seen as two closely allied fields: the creation of new bindings, and the repair of existing bindings. Bookbinders are often active in both fields. Bookbinders can learn the craft through apprenticeship; by attending specialized trade schools; by taking classes in the course of university studies, or by a combination of those methods. Some European countries offer a Master Bookbinder certification, though no such certification exists in the United States. MFA programs that specialize in the 'Book Arts,' (hand paper-making, printmaking and bookbinding) are available through certain colleges and universities.

Hand bookbinders create new bindings that run the gamut from historical book structures made with traditional materials to modern structures made with 21st-century materials, and from basic cloth-case bindings to valuable full-leather fine bindings. Repairs to existing books also encompass a broad range of techniques, from minimally invasive conservation of a historic book to the full restoration and rebinding of a text.

Though almost any existing book can be repaired to some extent, only books that were originally sewn can be rebound by resewing. Repairs or restorations are often done to emulate the style of the original binding. For new works, some publishers print unbound manuscripts which a binder can collate and bind, but often an existing commercially bound book is pulled, or taken apart, in order to be given a new binding. Once the textblock of the book has been pulled, it can be rebound in almost any structure; a modern suspense novel, for instance, could be rebound to look like a 16th-century manuscript. Bookbinders may bind several copies of the same text, giving each copy a unique appearance.

Hand bookbinders use a variety of specialized hand tools, the most emblematic of which is the bonefolder, a flat, tapered, polished piece of bone used to crease paper and apply pressure. Additional tools common to hand bookbinding include a variety of knives and hammers, as well as brass tools used during finishing.

When creating new work, modern hand binders often work on commission, creating bindings for specific books or collections. Books can be bound in many different materials. Some of the more common materials for covers are leather, decorative paper, and cloth (see also: buckram). Those bindings that are made with exceptionally high craftsmanship, and that are made of particularly high-quality materials (especially full leather bindings), are known as fine or extra bindings.

Conservation and restoration
Conservation and restoration are practices intended to repair damage to an existing book. While they share methods, their goals differ. The goal of conservation is to slow the book's decay and restore it to a usable state while altering its physical properties as little as possible; the goal of restoration, however, is to return the book to a previous state as envisioned by the restorer, often imagined as the original state of the book. In either case, the modern standard for conservation and restoration is "reversibility." That is, any repair should be done in such a way that it can be un-done if and when a better technique is developed in the future. Bookbinders echo the physicians' creed, "First, do no harm."

Books requiring conservation treatment run the gamut from the very earliest of texts to books with modern bindings that have undergone heavy usage. For each book, the conservator must choose a course of treatment that takes into account the book's value, whether it comes from the binding, the text, the provenance, or some combination of the three. Many professional book and paper conservators in the United States are members of the American Institute for Conservation of Historic and Artistic Works (AIC), whose guidelines, set forth in the AIC's Code of Ethics, are generally considered to outline an appropriate approach to the treatment of rare or valuable materials.

In restoration hand binding, the pages and book covers are often hundreds of years old, and the handling of these pages has to be undertaken with great care and a delicate hand. The binding archival process can extend a book’s life for many decades and is necessary to preserve books that sometimes are limited to a small handful of remaining copies worldwide.

The first step in saving and preserving a book is its deconstruction. The text need to be separated from the covers and, only if necessary, the stitching removed. This is done as delicately as possible. All page restoration is done at this point, be it the removal of foxing, ink stains, page tears, etc. Various techniques are employed to repair the various types of page damage that might have occurred during the life of the book.



The preparation of the "foundations" of the book could mean the difference between a beautiful work of art and a useless stack of paper and leather.

The sections are then hand-sewn in the style of its period into book form.

The next step is the creation of the book cover; vegetable tanned leather, dyed with natural dyes, and hand-marbled papers can be used. Finally the cover is hand-tooled in gold leaf. The design of the book cover involves such hand-tooling, where an extremely thin layer of gold is applied to the cover. Such designs can be lettering, symbols, or floral designs, depending on the nature of any particular project.

Terms and techniques
Most of the following applies only in respect of American practices:
 * A leaf or folio is a single complete page, front and back, in a finished book.
 * The recto side of a leaf faces left when the leaf is held straight up from the spine (that is, an odd-numbered page).
 * The verso side of a leaf faces right when the leaf is held straight up from the spine (or an even-numbered page).
 * A bifolio is a single sheet folded in half to make two leaves. Each half of the bifolio is a folio, though the terms are often used interchangeably.
 * A section, sometimes called a gathering, or, especially if unprinted, a quire, is a group of bifolios nested together as a single unit. In a completed book, each section is sewn through its fold. Depending of how many bifolios a section is made of, it could be called :
 * duernion – two bifolios, producing four leaves;
 * ternion – three bifolios, producing six leaves;
 * quaternion – four bifolios, producing eight leaves;
 * quinternion – five bifolios, producing ten leaves;
 * sextern or sexternion – six bifolios, producing twelve leaves.
 * A codex is a series of one or more sections sewn through their folds, and linked together by the sewing thread.
 * A signature is a section that contains text. Though the term signature technically refers to the signature mark, traditionally a letter or number printed on the first leaf of a section in order to facilitate collation, the distinction is rarely made today.
 * Folio, quarto, and so on may also refer to the size of the finished book, based on the size of sheet that an early paper maker could conveniently turn out with a manual press. Paper sizes could vary considerably, and the finished size was also affected by how the pages were trimmed, so the sizes given are rough values only.
 * A folio volume is typically 15 in or more in height, the largest sort of regular book.
 * A quarto volume is typically about 9 in by 12 in, roughly the size of most modern magazines. A sheet folded in quarto (also 4to or 4º) is folded in half twice at right angles to make four leaves. Also called: eight-page signature.
 * An octavo volume is typically about 5 to 6 in by 8 to 9 in, the size of most modern digest magazines or trade paperbacks. A sheet folded in octavo (also 8vo or 8º) is folded in half 3 times to make 8 leaves. Also called: sixteen-page signature.
 * A sextodecimo volume is about 4+1/2 in by 6+3/4 in, the size of most mass market paperbacks. A sheet folded in sextodecimo (also 16mo or 16º) is folded in half 4 times to make 16 leaves. Also called: 32-page signature.
 * Duodecimo or 12mo, 24mo, 32mo, and even 64mo are other possible sizes. Modern paper mills can produce very large sheets, so a modern printer will often print 64 or 128 pages on a single sheet.
 * A quire is a set of leaves which are stitched together. This is most often a single signature, but may be several nested signatures. The quires for a single book are arranged in order and then stitched together as a set.
 * Trimming allows the leaves of the bound book to be turned. A sheet folded in quarto will have folds at the spine and also across the top, so the top folds must be trimmed away before the leaves can be turned. A signature folded in octavo or greater may also require that the other two sides be trimmed. Deckle Edge, or Uncut books are untrimmed or incompletely trimmed, and may be of special interest to book collectors.

Paperback binding
Though books are sold as hardcover or paperback, the actual binding of the pages is important to durability. Most paperbacks and some hard cover books have a "perfect binding". The pages are aligned or cut together and glued. A strong and flexible layer, which may or may not be the glue itself, holds the book together. In the case of a paper back, the visible portion of the spine is part of this flexible layer.

Spine orientation
In languages written from left to right, such as English, books are bound on the left side of the cover; looking from on top, the pages increase counter-clockwise. In right-to-left languages, books are bound on the right. In both cases, this is so the end of a page coincides with where it is turned. Many translations of Japanese comic books retain the binding on the right, which allows the art, laid out to be read right-to-left, to be published without mirror-imaging it.

In China (only areas using Traditional Chinese), Japan, and Taiwan, literary books are written top-to-bottom, right-to-left, and thus are bound on the right, while text books are written left-to-right, top-to-bottom, and thus are bound on the left. In mainland China, all books have changed to be written and bound like left to right languages in the mid-20th century.

Spine titling
Early books did not have titles on their spines; rather they were shelved flat with their spines inward, and titles written with ink along their fore edges. Modern books display their titles on their spines.

In languages with Chinese-influenced writing systems, the title is written top-to-bottom, as is the language in general. In languages written horizontally, conventions differ about the direction in which the title on the spine is rotated:
 * In the United States, the Commonwealth and in Scandinavia, titles are usually written top-to-bottom on the spine. This means that when the book is placed on a table with the front cover upwards, the title is correctly oriented left-to-right on the spine. This practice is reflected in the industry standards ANSI/NISO Z39.41 and ISO 6357.
 * In most of continental Europe, titles are conventionally printed bottom-to-top on the spine so, when the books are placed vertically on shelves, the title can be read by tilting the head to the left.