Paper first penetrated Europe as a commodity from the 12th century onward through Italian ports that had active commercial relations with the Arab world and also, doubtless, by the overland route from Spain to France. Papermaking techniques apparently were rediscovered by Europeans through an examination of the material from which the imported commodity was made; possibly the secret was brought back in the mid 13th century by returning crusaders or merchants in the Eastern trade. Papermaking centres grew up in Italy after 1275 and by the 14th century a number of paper mills existed in Europe, particularly in Spain, Italy, France, and Germany. The invention of printing in the 1450s brought a vastly increased demand for paper. Through to the 18th century the papermaking process remained essentially unchanged, with linen and cotton rags furnishing the basic raw materials.
In 1800 a book was published that launched development of practical methods for manufacturing paper from wood pulp and other vegetable pulps. Several major pulping processes were gradually developed that relieved the paper industry of dependency upon cotton and linen rags and made modern large-scale production possible. These developments followed two distinct pathways. In one, fibres and fibre fragments were separated from the wood structure by mechanical means; and in the other, the wood was exposed to chemical solutions that dissolved and removed lignin and other wood components, leaving cellulose fibre behind. Made by mechanical methods, ground-wood pulp contains all the components of wood and thus is not suitable for papers in which high whiteness and permanence are required. Chemical wood pulps such as soda and sulphite pulp are used when high brightness, strength, and permanence are required. Ground-wood pulp was first made in Germany in 1840, but the process did not come into extensive use until about 1870. Soda pulp was first manufactured from wood in 1852 in England, and in 1867 a patent was issued in the United States for the sulphite pulping process.
Prior to the invention of the paper machine, paper was made one sheet at a time by dipping a frame or mould with a screened bottom into a vat of stock. Lifting the mould allowed the water to drain, leaving the sheet on the screen. The sheet was then pressed and dried. The size of a single sheet was limited to the size of frame and mould that a man could lift from a vat of stock.
In 1798 Nicolas-Louis Robert in France constructed a moving screen belt that would receive a continuous flow of stock and deliver an unbroken sheet of wet paper to a pair of squeeze rolls.
Although the paper machine symbolizes the mechanization of the paper industry, every step of production, from the felling of trees to the shipment of the finished product, has also seen a dramatic increase in mechanization, thus reducing hand labour. As papermaking operations require the repeated movement of large amounts of material, the design and mechanization of materials-handling equipment has been and continues to be an important aspect of industry development. Although modern inventions and engineering have transformed an ancient craft into a highly technical industry, the basic operations in papermaking remain the same to this day.