Type casting (typography)
From Wikipedia, the free encyclopedia
Type casting is a technique for casting the individual letters known as sorts used in hot metal typesetting by pouring molten metal into brass moulds called matrices.
Woodblock printing had been known in China for centuries. It was innovations in type casting that made for Gutenberg's breakthrough of commercially printing.[1] Although using matrices was a technique known well before his time, Johannes Gutenberg adapted their use to a conveniently adjustable hand mould, enabling one to easily and accurately cast identical multiple instances of any character.
The ultimate product of manual typecasting were letters, known as sorts for letterpress printing, and the process starts with the installation of a matrix with the impression of a particular glyph into the bottom of the hand mould which is adjusted for the width of the body and locked in preparation for casting. Molten type metal alloy would be carefully poured into a straight-sided vertical cavity at the top of the mould. The type caster would then give the mould a quick shake to aid the flow of type metal into every cavity of the matrix. In practice it was discovered that different glyphs would require different shakes to cast the characters properly. As the casting cooled down and solidified, the mould would be unlocked and the sort removed, ready for later finishing operations and locked again ready for the next character.
Manual casting was a long drawn-out process, but was able to produce precise and consistent excellent results.[1]
