Harry Ransom CenterThe University of Texas at Austin

What went on in Gutenberg's print shop?

Unfortunately, we don't have much concrete evidence about Gutenberg and his print shop. We do know that he operated at least one shop—perhaps two—in Mainz, but we don't know how many presses he owned or how many workers he employed. We can only speculate about his particular type-making and printing methods based on evidence in the surviving Bibles and what we know about early printing in general.

How was type made?

Traditionally, type making begins with the punch, a hard metal rod with a letter carved backward on its end. Because making punches by hand is a painstaking process, early printers relied on experienced craftsmen like goldsmiths.

The punch was driven into a plate of softer metal, leaving behind an impression of its letter. This piece of metal, the matrix, was then placed inside a mold. The mold was filled with hot liquid metal that quickly hardened into an individual piece of type.

The punch and matrix were reusable, and the same matrix was used to produce as many pieces of type as were needed for each character, or sort. Because all letters of the same sort were produced using a single punch and a single matrix produced from that punch, they all looked identical. This process is called the punch matrix system.

But how did Gutenberg make his type?

It was long believed that Gutenberg invented the punch matrix method. New research, however, questions this assumption. In 2001, two researchers at Princeton University, Paul Needham and Blaise Agüera y Arcas, studied Gutenberg's type by looking at close-up digital images of individual letters in his Bible. To their surprise, they found that the letters varied so much in appearance that no two pieces of type could have been cast from the same matrix. In other words, the punch matrix system might not have been what Gutenberg used after all.

Scholars have yet to agree on these new speculations. Needham and Agüera y Arcas think that Gutenberg may have used an earlier technology to make his type, using molds of sand. Because these molds had to be broken to remove the finished piece of type, a new mold had to be used for each individual piece. This technology had been used in Asia long before Gutenberg's time.

Gutenberg's type supply

The amount of type needed to print all the copies of Gutenberg's Bible must have been enormous. About 300 different sorts of type were needed, including uppercase and lowercase letters, punctuation marks, special characters, and common abbreviations. Scholars estimate that each page required approximately 2,600 individual pieces of type.

How was a page printed?

We know almost nothing about how Gutenberg set his type or printed his Bible, but we do know quite a bit about traditional printing techniques in later years.

Early printers set type by arranging individual pieces of type in a line on a tool known as a composing stick. The person who did this work was known as the compositor, and he worked from a manuscript. Once each line of type was completed, it was moved off the composing stick onto a board known as a galley. When enough lines of type were stacked on top of one another to make a page or a column, they were tied together and locked into a frame called a chase.

The chase was placed in a construction called a form, which was in turn placed in the bottom portion, or bed, of the press. Printers spread ink on the form using tools known as ink-balls. The ink-balls, balls of wool covered in leather and attached to wooden handles, were first coated in a sticky oil-based ink and were then beaten against the form.

Finally, dampened paper was placed over the inked chase, and with a hard pull on the press, a heavy plate, or platen, was brought down onto the other side of the paper. This pressure caused the raised surfaces of the type to leave behind their impressions in ink on the paper.

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