Three surfaces for writing
AFor more than four thousand years, the history of writing has also been a history of the surfaces people wrote on. Three materials dominated the ancient and medieval world: papyrus, parchment and paper. Each solved some problems and created others.
BPapyrus was produced in Egypt from a tall reed that grew along the Nile. Makers cut the stem into thin strips, laid one layer vertically and a second layer horizontally on top, and then pressed and dried the sheet; the plant's own sap helped to bind the layers. Sheets were pasted together end to end to form rolls, some several metres long. Papyrus was light and, because the reed was abundant, relatively cheap in Egypt. Its weakness was moisture: in damp climates it became brittle and decayed, which is why most surviving papyri come from the dry sands of Egypt rather than from northern Europe.
CParchment was made from animal skin, usually that of calves, sheep or goats. Ancient writers linked it with the city of Pergamon in Asia Minor, although the story that it was invented there is probably a legend. Production was slow. First the skin was soaked in a lime solution for several days, which loosened the hair. The hair was then scraped away, and the wet skin was stretched on a wooden frame. As it dried under tension, the worker shaved it thinner with a curved knife, and finally rubbed the surface with pumice to make it smooth enough to hold ink. The result was strong and could be written on both sides, which made it well suited to the codex, the bound book with pages. Its great disadvantage was cost: a single large book might need the skins of an entire flock.
DPaper came from China. Chinese records credit an official called Cai Lun with improving the process in 105 CE, using bark, hemp and old rags that were beaten into a pulp, spread on a screen and dried. Paper reached the Islamic world by the eighth century, and mills in Baghdad were producing it soon afterwards. From there the technique spread to Spain and Italy. Paper was far cheaper than parchment because its raw materials were largely waste, and this low cost later made it the natural partner of the printing press.