A mechanical typesetting method where molten lead alloy is injected into molds to cast solid lines of type or individual characters. The metal cools instantly into a solid slug, which is then arranged into pages for letterpress printing. Once the printing is done, the slugs are melted down and reused.
The shop still keeps a hot metal machine running for specialty letterpress jobs and foil stamping.
The alloy used is typically a mixture of lead, tin, and antimony, which expands slightly upon cooling to fill the matrix precisely.
Also heard as
- hot lead
Related terms
Linecasting
The automated process of casting complete lines of text in molten lead.
Letterpress
A relief printing process where raised, inked surfaces are pressed directly onto paper.
Slug out
To quickly cast lines of type using a hot-metal linecasting machine.
Matrix
A metal mold used to cast individual type characters or entire lines of text.