He invented the movable type press, which (eventually) made books cheap enough for everyone to have a Bible. (Not a Gutenberg Bible, though... he went broke before he got the process perfected to the point of allowing mass production.)
Did he use lead in the ink, too?
Born 1399, died 1468.
Gutenberg's father was a metalworker who apparently had some connections to the mint in Mainz, and it was probably in his father's shop that he learned about metal casting and the use of punches. As an adult, Gutenberg seems to have experimented with using cast metal plates to print books, instead of the carved wood blocks much more commonly used. Somehow he got the idea to assemble printing masters from small units bound together, instead of casting a plate for a whole page at once. That was the key idea, but then he had to figure out how to make it practical. To achieve this, Gutenberg made four separate technological innovations, each brilliant:
Gutenberg faced much greater challenges than someone inventing, say, movable type to produce modern Times Roman font would. Scribes of his period used brushes [and quills] to paint letters on expensive books; the letterforms showed complex variations in line weight as an artifact of relatively easy hand movements. The scribes added many edge marks and tiny squiggles that we'd recognize as apostrophes and accent marks today, and they used hundreds of easily-written shorthand symbols for common words to save themselves from RSI. Modern symbols like & and Xmas are among the few of these marks still in use.
To meet his customers' expectations, Gutenberg could not print books using only the 100 or so glyphs we'd now expect. And he could not simplify each glyph's shape into something easy to mold but hard to draw. This was long before folks had learned to continually adapt their culture to new technology, no matter how compelling its benefits: Gutenberg could not deliver the equivalent of a cheap dot-matrix printer. He had to match all this legacy manuscript baggage in his typefaces first before ever producing anything salable. --PCP
This invention has been used basically unchanged until the latter half of the 20th century, when the offset printing technique became popular. In essence, offset printing is a return to block printing, except that the blocks are replaced by metal plates. By using a photographical process, part of the plate is etched away, and the resulting plate can be used to print books.
The advantage is that you can use this to print a computer-generated page. Note, however, that the first typesetting programs were so inferior to human typesetters that DonaldKnuth felt himself obliged to write TeX, for the main purpose of correctly typesetting his magnus opus TheArtOfComputerProgramming.