Printing

Although a technology in which seals were first pressed into damp clay tablets is known to have been used by the Babylonians, the Chinese probably invented printing. They used carved stones for making copies by first sprinkling soot over the carving, then placing a piece of paper on it and rubbing until the ashes came off on the stone. The oldest known printings were produced in China 1,200 years ago. They consisted of Buddhist texts, and were made using ink blocks and small pieces of paper.

Around 800 years ago, the Chinese printer Pi Sheng first formed Chinese characters out of bits of clay. He found that by fitting the clay pieces together to spell out words, he could print entire texts. These clay pieces, which would now be called movable type, had the advantage that they could be reused. Later type was made out of wood.

In Korea, pieces of type were placed in a box, or form, so that they spelled out words. By pressing the form against wet sand, the individual pieces created impressions in the sand. Molten metal was then poured over the sand, so that it filled the letter-shaped impressions. When the metal cooled, a solid plate with raised images of the characters was formed. This metal plate was then used to print on paper. The metal plate proved easier to work with than did movable type. While a page was being printed using the metal plate, the original movable type was reassembled to make another plate. This technique is still in use, and is known as type mold. By A.D. 1400, Korea had the most advanced printing technology, and even commoners there were able to own copies of official publications.

In Europe, meanwhile, the Romans had not discovered printing, and all books were produced by hand. By about A.D. 1000 most of these handwritten books had been destroyed, and the few that survived were carried off to the East. Some of the surviving books were later returned to Europe by scholars and priests. There, scribes in monasteries made copies by hand. Each of these handwritten books required many hours of skilled labor to produce, and only the wealthy could afford to own books.

Around 1400, Europeans began to experiment with news ways to make books. They had no knowledge of Chinese printing technologies, and developed methods of printing independently of what was happening on the other side of the world. Some Europeans rediscovered the use of carved blocks, the technology the Chinese had used before they came upon the idea of movable type. But block printing was too slow and expensive to meet the rising demand for books.