Hot Lead, Cold Type, and Little Digital Bits: Part I

In 1450, the process for creating books—whether in codex or scroll form—was to sit for several weeks with a pen and inkpot and copy a work letter-for-letter. By 1460, just 10 years later, the printing press had spread throughout Europe and was being used to mass-produce books. It all had to do with the invention of little pieces of metal type that each bore an individual character on it. Getting those bits of metal required several inventions, most of which we credit to Johannes Gutenberg.

 

First, there was the type design. The type used in the Gutenberg Bible was patterned after that found in a manuscript Bible of Mainz, which also served as the guide for setting the pages. While the Latin alphabet included only the basic 26 letters used today, Gutenberg’s design included as many as 250 different glyphs that spanned upper and lower case letters, punctuation, abbreviations, characters in various widths, and ligatures (double characters combined into a single glyph). For every character in the text, about 1/4 inch or 18 points in size, a punch had to be engraved. The punch was the perfect reverse of the letter form.

 

Then there was the matrix, or mold for the type itself. The punch was designed to make the impression in the mold into which the the hot lead was poured. The mold had to be reusable because many copies of each character were needed to keep the manufacturing process moving. If any letters were damaged in the process, they also had to be replaced.

 

Third, there is the alloy itself—one of the most remarkable parts of the invention. Movable type in clay and wood had been in use in China for some time, and there were already experiments in metal type in Korea at the time of Gutenberg. It seems unlikely that Gutenberg knew about these, but woodblock printing was certainly known in Western Europe by Gutenberg’s time. The problems with these various predecessors had to do first with the durability of the type to withstand repeated impressions under the pressure of the press, and the uniformity of the type. Even early printing examples from Gutenberg’s shop before the Bible show an unevenness in the height of the type causing a dark impression for some letters and a lighter impression for others.

 

This is where Gutenberg’s experience as a goldsmith and perhaps even as an alchemist came into play. Rumors of his experimentation in alchemy have certainly been fueled by the composition of the lead alloy used in the type—lead, tin, and antimony—the same elements used in the most prevalent alchemical formulae. Antimony, a highly toxic metal, has the unusual property of expanding as it cools from molten to solid, unlike the other metals in the mix, which contract. The combination of the expanding antimony with the contracting lead and tin resulted in a dimensionally stable alloy, so every character retained the exact shape and size of the mold.

 

In The Gutenberg Rubric, incunabulist Keith Drucker must master the art of casting the dimensionally stable alloy using only the measuring tools of Gutenberg’s day. The result of his work is crucial to unlocking the secret of Gutenberg’s code.

 

(The Gutenberg Rubric, a novel by Nathan Everett, will be released on July 28. Order your copy today!)