The early Chinese method used materials that were cheap and plentiful. Bark from the paper mulberry tree, hemp fibers, and old cloth were soaked in water, often for a long time, and sometimes cooked with wood ash or lime to soften them. The softened material was pounded in a mortar until the fibers separated and formed a pulp. The pulp was mixed with water in a large vat. To form a sheet, the papermaker used a mould: a frame holding a screen. In the earliest moulds, the screen may have been a length of woven cloth stretched across the frame. Later, a more convenient type of mould used a flexible screen made of thin strips of bamboo held together with silk or horsehair threads.
With the bamboo-screen mould, a skilled worker dipped the mould into the vat, lifted it out with a thin, even layer of pulp on the screen, and shook it gently so that the fibers spread evenly as the water drained away. The flexible screen could then be lifted from its frame and laid face down on a pile of earlier sheets, leaving the newly formed wet sheet behind. The screen was set back in the frame and dipped again. Because the screen could be removed and reused at once, a single worker could form many sheets in an hour. The pile of wet sheets was pressed to remove water, and the sheets were then separated and brushed onto heated walls or other smooth surfaces to dry.
Over time, Chinese papermakers developed a wide range of papers for different purposes. Some were thin and translucent, suited to copying. Some were thick and absorbent, suited to ink brushes. Some were treated with substances that discouraged insects, a valuable feature for documents that needed to be kept for many years. Paper came to be used not only for writing but also for wrapping, for screens and windows, for lanterns, and for clothing and household goods. By the period of the Tang dynasty, in the seventh to tenth centuries, paper was produced in large quantities and was an ordinary part of daily life.
Paper also made possible the development of printing in China. Printing from carved wood, in which a whole page of text was carved in relief on a flat wooden plate, inked, and pressed onto paper, was in use by the eighth century. One of the earliest dated printed works that survives was produced in the year 868. Printing created a steady demand for paper and encouraged the production of sheets with consistent quality and size. Later, experiments with individual characters made from baked clay and other materials were recorded in the eleventh century, though printing from carved wood remained the dominant method in China for many centuries.
From China, papermaking spread to neighboring regions. It reached Korea, and by the early seventh century it had been carried to Japan, where a tradition is told of a Buddhist monk from Korea who brought knowledge of papermaking and ink making to the Japanese court. Japanese papermakers developed their own methods and materials, using the inner bark of several native shrubs. The papers they produced, known for their strength and fine texture, became highly valued and are still made by hand today. Papermaking also spread to Vietnam and to parts of Central Asia along the trade routes that linked China with the lands farther west.
IV. The Westward Spread
Papermaking traveled westward slowly. For several centuries after it was well established in China, paper was known in Central Asia and the Middle East mainly as an imported good.