Gutenberg’s Second Invention

After the breakup of his partnership with Johann Fust in the Bible project, Gutenberg continued to print small items using his first, DK type, including broadside calendars and the 1456 Bulla Thurcorum. He then conceived a second ambitious process for book printing, by which typesettings could be preserved and reprinted, without the necessity of recomposition. Using a new typefont, a small and simplified rotunda, Gutenberg’s shop set type-pages, and then, after proofing, separated them into line-pairs, which were impressed into a medium such as clay or fine sand to create a second matrix. Over these matrixes hot typemetal was poured, creating a permanent, thin two-line strip.

Thus, the Catholicon Press books were printed not directly from the types, but from the secondary two-line strips, assembled by pages in correct text order. After printing, the strips were stored, page by page, and could be quickly reassembled for reprints. This process would have been slower and more expensive than conventional movable-type printing. The chief investor was a wealthy Mainz citizen and canon lawyer, Dr. Konrad Humery. After Gutenberg’s death in early 1468, Humery claimed ownership of all of Gutenberg’s typographic equipment, a major part of which would have been the thousands of two-line strips comprising the full texts of two brief religious tractates by St Thomas Aquinas and Matthew of Cracow, and the massive Catholicon dictionary of Johannes Balbus. No other books were printed by this process, but it was not entirely forgotten, for in the sixteenth century some map printers used cast line strips in just the same way, to insert place names into woodblocks of maps.