The earliest known printed books were produced using wooden blocks with the text carved on them which was then used as a printing plate. However, for most of the history of publishing some form of "hot metal" or "foundry" movable type has been used. This was invented in 1448 by the German printer Johann Gutenberg, and by 1462 it was becoming accepted throughout Europe. Every single letter, number or other character was cast in a metal alloy, so that each piece of type contained a single raised (mirror) image. Newspapers continued to use a version of this system until the 1980s, but today almost all type is set electronically. See Brown, R. J., A Capsule History of Typesetting,
<http://www.serve.com/ephemera/library/reftype.htm>.

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