The word paper comes from the ancient Egyptian writing material called papyrus, which was woven from papyrus plants. Papyrus was produced as early as 3000 BCE in Egypt, and in ancient Greece and Rome. Further north, parchment or vellum, made of processed sheepskin or calfskin, replaced papyrus, as the papyrus plant requires subtropical conditions to grow. In China, documents were ordinarily written on bamboo, making them very heavy and awkward to transport. Silk was sometimes used, but was normally too expensive to consider. Indeed, most of the above materials were rare and costly.

The Chinese court official Cai Lun (蔡倫) described the modern method of papermaking in AD 105; he was the first person to describe how to make paper from wood pulp. Archeologically, true paper had been excavated in China dated from the 2nd century BC. It spread slowly outside of China; other East Asian cultures, even after seeing paper, could not figure out how to make it themselves. Instruction in the manufacturing process was required, and the Chinese were reluctant to share their secrets. The technology was first transferred to Korea in 600 and then imported to Japan by a Buddhist priest, Dam Jing (曇徴) from Goguryeo, around 610, where fibres (called bast) from the mulberry tree were used. After further commercial trading and the defeat of the Chinese in the Battle of Talas, the invention spread to the Middle East, where it was adopted in India and subsequently in Italy in about the 13th century. They used hemp and linen rags as a source of fiber. Rags from old clothing, etc. were commonly bought by rag collectors and sold to paper makers. As printing on rag paper became more popular, the supply of rags became more and more inadequate and other sources of fiber were actively sought. A great deal of experimentation took place. The oldest known paper document in the West is the Missel of Silos from the 11th century.

Some historians speculate that paper was the key element in global cultural advancement. According to this theory, Chinese culture was less developed than the West in early ancient times because bamboo, while abundant, was a clumsier writing material than papyrus; Chinese culture advanced during the Han Dynasty and preceding centuries due to the Chinese invention of paper; and Europe advanced during the Renaissance due to the introduction of paper and the printing press. Papermaking was one of the Four Great Inventions of ancient China. Paper remained a luxury item through the centuries, until the advent of steam-driven paper making machines in the 19th century, which could make paper with fibres from wood pulp. Although older machines predated it, the Fourdrinier paper making machine became the basis for most modern papermaking. Together with the invention of the practical fountain pen and the mass produced pencil of the same period, and in conjunction with the advent of the steam driven rotary printing press, wood based paper caused a major transformation of the 19th century economy and society in industrialized countries. Before this era a book or a newspaper was a rare luxury object and illiteracy was the norm. With the gradual introduction of cheap paper, schoolbooks, fiction, non-fiction, and newspapers became slowly available to nearly all the members of an industrial society. Cheap wood based paper also meant that keeping personal diaries or writing letters ceased to be reserved to a privileged few. The office worker or the white-collar worker was slowly born of this transformation, which can be considered as a part of the industrial revolution.

A rather loose description of how paper is made by hand: Fibers are floated in a slurry, a thick soup of water and fibers, in a large vat. A wire screen mould with a wooden frame (somewhat similar to an old window screen) is used to scoop some of the slurry out of the vat. The wooden frame is called a "deckle." The impressions in paper caused by the wires in the screen that run sideways are called "laid lines" and the impressions made, unusually from top to bottom, by the wires holding the other wires together are called "chain lines." Watermarks are created by weaving a name into the wires in the mould. This is also basically true of Oriental moulds made of other substances, such as bamboo. Hand-made paper generally folds and tears more evenly along the laid lines.

The wooden frame or deckle leaves the edges of the paper slightly irregular and wavery. This wavy edge is called the "deckle edge" and is one of the indications that the paper was made by hand. Deckle-edged paper is occasionally mechanically imitated today to create the impression of old-fashioned luxury.

Returning to the process: the slurry in the screen mould is artfully sloshed around the mould until it forms an over-all thin coating. The fibers are allowed to settle and the water to run out. When the fibers have stabilized in place but are still damp, they are turned out onto a felt sheet (which oddly enough was made by a similar "matting" process) which was generally made of an animal product such as wool or rabbit fur, and the screen mold immediately reused. Layers of paper and felt build up in a pile and a weight is placed on top to press out water and keep the paper fibers flat and tight. When the paper pages are dry, they are frequently run between rollers to produce a harder writing surface. Papers are made of different surfaces depending on their intended purpose. Paper intended for printing or writing with ink is fairly hard, while paper to be used for water color, for instance, if fairly soft.

Unfortunately, the wood-based paper was more acidic and more prone to discolor and disintegrate over time, through processes known as slow fires. Documents written on more expensive rag paper were more stable. Both rag and woodpulp paper will develop tan spots called "foxing" caused by impurities or fungi reacting with humidity. The majority of modern book publishers now use acid-free paper. Modern newspapers are commonly printed on cheaper high-acid paper which turns tan and disintegrates rather rapidly, especially in the presence of strong light and humidity.

In the beginning of Western papermaking, the paper size was fairly standard. A page of paper is referred to as a "leaf." When a leaf was printed on without being folded, the size was referred to as "folio." It was roughly equal to the size of a newspaper sheet.

When it was folded once, it produced four sides or pages, and the size of the pages or a book made of such pages was referred to as "quarto" (4to).

If the original sheet was folded in half again, the result was eight sides, referred to as "octavo" (8vo), which is the size that most books, such as the average novel, use to this day.

An "octavo" folding produces four leaves, the first two and the second two will be joined at the top by the second fold. The top edge is usually "trimmed" to make it possible to look freely at each side of the leaf. However, many books are found that have not been trimmed on the top, and these pages are referred to as "unopened." Many people reading "unopened" books will use their finger, a pencil, or some other inadequate instrument to rip open the top of the pages, leaving an irregular tear. A letter opener or a knife carefully used is a more appropriate tool.

An octavo book produces a printing puzzle. Pieces of paper are printed when they are folio size. To provide for the proper alignment of numbered pages, pages 8 and 1 are printed right-side-up on the bottom of the sheet, and pages 4 and 5 are printed up-side-down on the top of the same sheet. On the opposite side, pages 2 and 7 are printed right-side-up on the bottom of the sheet, and pages 6 and 3 are printed up-side-down on the top of the sheet. When the paper is folded twice and the folds trimmed, the pages fall into proper order.

Try folding a paper in half by turning the top half down and creasing it, and then fold it in half again by turning the left side over the right. You have the format for an octavo page arrangement. If you number the pages in order and then open the paper to full size, you will see the numbers as described above.

Smaller books are produced by folding the leaves again to produce 16 pages, known as a "sixteen-mo" (16mo). Other folding arrangements produce yet smaller books such as the thirty-two-mo (32mo).

When a standard-sized octavo book is produced by a large leaf folded two times, two leaves joined at the top will be contained in the resulting fold (which ends up in the gulley between the pages). This group of 8 numberable pages is called a "signature" or a "gathering." Traditionally, printed signatures were stacked on top of each other in a "sewing frame" and each signature was sewn through the inner fold to the signature on top of it. The sewing ran around leather bands or fabric tapes along the backs of the signatures to stabilize the growing pile of signatures.

The leather bands originally used in the West to stabilize the backs of sewn books appear as a number of ridges under the leather on the spine of leather books.

The ends of the leather strips or fabric bands were sewn or glued onto the cover boards and reinforced the hinging of the book in its covers.

See also

• Four Great Inventions of ancient China
• Paper

Standard reference book on the subject: PAPERMAKING, The History and Technique of an Ancient Craft, by Dard Hunter, Alfred A. Knopf, NY, 1943.

Paper

造纸术