Living in the information age means being constantly bombarded with printed matter in all shapes and forms. The significance of printing may occasionally be obscured by the ubiquity of these printed materials, especially when they arrive in the mail, unsolicited. Yet printing is one of the most indispensable elements of our civilization, perhaps second only to agriculture. The spread of literacy that enabled the masses to read and write, the accumulation and growth of knowledge which precipitated the agricultural, then the industrial, and now the electronic revolution, as well as the spread of ideas that shaped changes in social and political relations, are all made possible by advances in printing.
Printing began in China. During the later Han Dynasty (25â220), at the time of the Five Good Emperors of the Roman Empire, the Chinese already possessed the three necessary ingredients of printing: recording medium (paper), writing material (ink) with which to delineate patterns on the recording medium, and templates (reliefs on seals and marble pillars) from which replicas were made. Paper was invented in the year 105 by Cai Lun, who formed sheets from macerated tree bark, hemp waste, rags, and fishing-nets; ink was in use since about 2500 B. C.; the pillars and seals often bore religious pictures and texts.
This early form of printing was impractical because of the size and workmanship requirement of the templates. Wood blocks were used as substitutes by the sixth century. Prints were made by inking the engraved wood block, and then rubbing with a brush the back of a sheet of paper placed on the block. The next major advancement came in the 1040s, when Bi Sheng invented the movable type made of a mixture of clay and glue hardened by baking. This technique, nevertheless, idled in China.
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