[Guest Article] Gutenberg’s Inventions – Part 2: Hand Mould

In our series, guest author Dr. Julia Bangert from the International Gutenberg Society introduces the inventions of Johannes Gutenberg. The second edition is all about the hand mould.

© Header: Markus Kohz

The hand mould is the heart of Johannes Gutenberg’s invention and the only part of the printing process for which he could not fall back on any existing model. It consists of a two-part rectangular hollow metal mould with a channel for filling the liquid metal alloy. The mould is surrounded by a wooden frame so that the instrument can be held in the hand when pouring the hot metal alloy. The matrix is clamped at the lower end of the casting channel and fixed with a metal spring. The matrix can be adjusted according to the type size and width. Now everything is ready for casting the type.

 

The Alloy

We do not know the composition of Gutenberg’s original alloy, but it can be reconstructed by later descriptions. It consisted largely of lead, to which tin and antimony were added, and very little copper and iron. The advantage of this mixture is that it becomes solid and cold immediately after being filled into the hand mould and the cast sort can be removed directly. In this way it was possible to produce many identical pieces of type in quick succession.

 

The Sprue

If you remove the pieces of type from the hand casting instrument, they still have an excess piece of metal at the upper end. This part is knocked off at the predetermined breaking point provided for it. The pieces of type are then carefully filed to the correct height so that all of them have the same height at the end. This is important in order to obtain an evenly printed text. Because if one piece of type is too high in relation to the others, it presses too hard into the paper, if it is too low, its letter will not print properly. You can read more about the type and how it is stored in the type case in part 3 of our series “Gutenberg’s inventions”.

“Der Schrifftgiesser” (Woodcut; in: “Ständebuch”, 1568)

 

Über die Autorin:
Dr. Julia Bangert, Copyright: cross-effect

Julia Bangert has a PhD in book studies and is an artist. Her dissertation entitled “Buchhandelssystem und Wissensraum in der Frühen Neuzeit” was published in 2019. In addition to her work as Managing Director of the International Gutenberg Society, she works as a book painter and illustrator. Finest colouring and an elegant brush stroke are her trademarks, a perfect gilding is her passion.