Paper

Paper is one of the great inventions of China, taking its place alongside the compass, gunpowder and printing. Its manufacture is traditionally credited to Cai Lun, a court official of the Later Han period, in about 105 CE. Archaeological evidence nevertheless shows primitive hemp paper types from the 2nd century BCE, pushing the material's origins well back before that date.

Cumbersome bamboo or wooden strips and expensive silk had served for centuries as writing surfaces before paper scrolls offered a lighter and cheaper alternative. When Muslim armies conquered Central Asia in the late seventh and early eighth centuries they encountered paper for the first time. From Iraq papermaking was carried to Syria, then Egypt, across North Africa to Morocco and eventually to Spain, where its use is first recorded by a tenth-century traveler. Fez was already an important papermaking center in the 11th century, with 400 paper mills reported by the end of the 12th century, and the first Spanish paper mill is documented at Jativa in 1056.

Papermaking was begun in Baghdad itself by the late 8th century. Papermaking and stationery were soon significant businesses there, and the city's Stationers' Market was a street lined with more than 100 paper- and booksellers' shops. Rattan replaced the early hemp paper and was favoured for centuries, until bamboo fibres became the most common raw material from the 8th century CE. From the Song Dynasty the main raw material became the boiled bark of the mulberry tree. Around 1023 CE the Song government issued paper certificates indicating money held on deposit in Szechwan, an ancestor of paper money. Around 1120 CE the Chinese government established a monopoly on the issue of such receipts, in effect creating the world's first banknotes.

Paper reached the Korean peninsula and the Japanese archipelago along the routes that carried Buddhist learning and administrative practice. In Japan tradition credits the Korean monk Don-cho with the introduction of papermaking about AD 610. The Japanese first used paper only for official records and documentation, but with the rise of Buddhism the demand for paper grew rapidly.

The distinctive Japanese handmade paper known as washi is built from the inner-bark fibres of three plants: kozo, gampi and mitsumata. The highest quality mitsumata fibres are used to make the paper that Japanese bank notes are printed on. Washi serves letter writing, books and documents, and also home interiors such as paper screens, room dividers and sliding doors.

Today most paper in Japan is made in large automated mills, but a few hundred families in rural villages continue to make washi in the traditional way. Washi craftsmanship was inscribed in 2025 on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity.

By the reign of the Abbasid caliph Harun al-Rashid enough paper was available in Baghdad for bureaucrats to use for record-keeping, and the vizier al-Fadl ibn Yahya introduced the manufacture of paper there. The word for a bundle of sheets carries this commerce into English: paper is still counted in units of 500 sheets called reams, a term that reached English via Old French and Spanish from the Arabic rizmah, meaning a bale or bundle.

European paper-making drew on rag cloth as its raw material, and the transformation of that cloth into paper paste was obtained by the Fabriano paper makers using the hydraulic multiple hammer mill. The multiple hammer hydraulic mill, suggested by the fulling hammers operated by water wheels, eliminated the stone mortar and wooden piston operated by hand that had been used by the Arabs. To eliminate the deterioration of sheets sized with wheat starch, the Fabriano paper-makers substituted gelatine or animal sizing extracted from the discarded meat of the local tanners.

The essential sheet-forming tool was the mould, a rectangular wooden frame covered with a woven brass-wire surface and fitted with an open frame called a deckle that determined the outer dimensions of the finished paper. Modern paper machines use a dandy roller to obtain watermarks, or watermark bodkins for impressed watermarks.

The German Ulman Stromer, who had seen paper mills in Italy, built the first one north of the Alps at Nuremberg in the late 14th century. In England, John Spilman, Queen Elizabeth's jeweller, established a paper mill in Dartford, Kent, in 1588 to manufacture white writing paper, producing the first writing and printing paper in England since John Tate's short-lived paper mill in the late fifteenth century.

The invention of printing in the 1450s brought a vastly increased demand for paper, and through the 18th century paper mills were increasingly plagued by shortages and even advertised publicly for rags.

European resistance to paper is illustrated by a decree of 1221 from Holy Roman Emperor Frederick II, which declared all official documents written on paper to be invalid.

The material of choice for the European papermaker was cotton or linen fiber from rags, sorted, cleaned and heated in a solution of alkali. The rags themselves were collected by rag-and-bone men, a trade in existence in England since the Middle Ages, who led a horse and wagon around villages calling out for rags and bones; the rags were then sold to rag merchants by weight and quality and became an important part of the paper making industry. The major centre of Italian paper manufacture developed after 1276 at Fabriano in central Italy, and European water power made its paper cheaper than that of North Africa and Egypt.

After 1800 hand papermaking was rapidly changed by the papermaking machine, chlorine bleach, rosin and alum internal size, and impure wood-pulp fibres substituted for rags. In 1798 Nicolas-Louis Robert in France constructed a moving screen belt that would deliver an unbroken sheet of wet paper, and in 1807 two English engineers built an improved version for Henry and Sealy Fourdrinier. The Fourdriniers had taken out their first patent in 1801 and in 1807 perfected their machine for making continuous paper. Its chief advantages were that it produced paper of any size and with greatly increased rapidity; when the invention was completed the Fourdriniers had expended £60,000 and become bankrupt. William Rittenhouse established British America's first paper mill on the Monoshone Creek in 1690, and it was the only paper mill in the colonies for twenty years. Home to that first mill, Philadelphia went on to be the nation's primary papermaking center through the early nineteenth century. In 1816 Thomas Gilpin patented the nation's first papermaking machine and the following year put it into operation at his family's Brandywine Paper Mill. Groundwood pulp was first made in Germany in 1840 and soda pulp was first manufactured in England in 1852 while in 1867 a United States patent was issued for the sulfite pulping process. By 1875 paper coated by machinery was being made for halftone printing, and in 1884 Carl F. Dahl invented sulfate (kraft) pulp in Danzig, Germany.

Before 1800 paper sheets were sized by impregnation with animal glue or vegetable gums; in 1800 Moritz Friedrich Illig discovered that paper could be sized in vats with rosin and alum. The discovery of the element chlorine in 1774 led to its use for bleaching paper stock. Wood pulp paper produced before the 1980s tends to be acidic because of alum-rosin sizing, which in the presence of moisture generates sulfuric acid. In the 1980s, paper manufacturers began adding alkaline buffers to wood pulp papers intended for lasting use; these buffers retard or prevent acid hydrolysis.

A number of important discoveries were made on the Zaan, including the beater tub known as the Hollander, which reduced the time involved in preparing the pulp by 75 percent. After 1800 the device came into universal acceptance across the trade. At the end of the 17th century there were some 40 paper mills in the Zaan region, all equipped with two or three beater tubs.

Xuan paper is made by hand from the bark of the Tara Wing-Celtis together with rice straw, and its character is defined by the way it absorbs water and moistens ink. The craft is rooted in Jing County in Anhui Province, where the quality of the water and a mild climate are counted among its essential ingredients. Production follows a strictly manual course of more than a hundred steps and takes more than two years to complete. The industry sustains a substantial share of the local population, employing about one in nine residents of Jing County.

• 140–86 BC
  Xuanquanzhi fragments
  Earliest known paper fragments.
• 751
  Talas
  Papermaking knowledge spreads beyond China.
• 793
  Baghdad paper
  Paper production in Baghdad.