Paper-making

The art, science, information and technology of papermaking addresses the methods, equipment, and materials used to make paper and cardboard, these being used widely for printing, writing, and packaging, among many other purposes and useful products. Today almost all paper is manufactured using industrial machinery, while handmade paper survives as a specialized craft and a medium for artistic expression.

In papermaking, a dilute suspension consisting mostly of separate cellulose fibres in water is drained through a sieve-like screen, so that a mat of randomly interwoven fibres is laid down. Water is further removed from this sheet by pressing, sometimes aided by suction or vacuum, or heating. Once dry, a generally flat, uniform and strong sheet of paper is achieved.

Before the invention and current widespread adoption of automated machinery, all paper was made by hand, formed or laid one sheet at a time by specialized laborers. Even today those who make paper by hand use tools and technologies quite similar to those existing hundreds of years ago, as originally developed in China and Asia, or those further modified in Europe. Handmade paper is still appreciated for its distinctive uniqueness and the skilled craft involved in making each sheet, in contrast with the higher degree of uniformity and perfection at lower prices achieved among industrial products.

While monitoring, regulations and action by concerned citizens, as well as improvements within the industry itself are limiting the worst abuses, papermaking continues to be of concern from an environmental perspective, due to its use of harsh chemicals, its need for large amounts of water, and the resulting contamination risks, as well as trees being used as the primary source of wood pulp. Paper made from other fibers, cotton being the most common, tends to be valued higher than wood-based paper.

Papermaking is traced back to China about 105 CE, when Cai Lun, an official attached to the Imperial court during the Han Dynasty (202 BCE-220 CE), created a sheet of paper using mulberry and other bast fibres along with fishnets, old rags, and hemp waste. Paper with legible Chinese writings on it dating from 8 BCE, Cai Lun and his predecessors on the basis of previous bleaching and the production of paper on the basis of summary and improve,the paper production transferred to an independent industry from raw materials and technology, used for writing.The "Cai Lun paper" is not Cai Lun a hand crafted, but not his "made" by the imperial craftsmen also cannot manufacture this kind of plant fiber paper. while hempen paper had been used in China for wrapping and padding since the eighth century BCE. Paper used as a writing medium became widespread by the 3rd century and, by the 6th century, toilet paper was starting to be used in China as well. During the Tang Dynasty (618-907 CE) paper was folded and sewn into square bags to preserve the flavour of tea, while the later Song Dynasty (960-1279 CE) was the first government to issue paper-printed money.

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