type bar
A line of type cast in one piece, as in a linotype or typograph.
type bar: a single line of metal type for fast printing
A type bar is a solid, single-piece casting of an entire line of type, used primarily in linotype and similar hot-metal composition machines. Unlike individual sorts that must be set letter by letter, a type bar emerges from the casting mechanism as one continuous slug, typically ranging from 6 to 14 inches long and roughly 0.2 inches deep. The face of the bar carries raised characters that transfer ink and impression to paper.
In a linotype machine, the operator uses a keyboard to select matrices (molds) for each character needed. These assemble horizontally in a stick, and molten type metal is forced into the matrix cavity under pressure. The metal cools almost instantly; the resulting type bar drops into a galley or tray ready for printing. Each bar sits on a surface called the feet, which rest on the press bed. The speed of production, rarely exceeding 6 to 7 lines per minute even on fast machines, was revolutionary compared to hand composition but still constrained by metal cooling time and the mechanical feed system.
Variants and practical limits
Newspaper shops and commercial printers preferred wider measures (deeper lines) for efficiency; advertising and job shops sometimes cast narrower bars for flexibility. Monotype machines, by contrast, cast individual characters instead of full lines. Type bars could be melted down and recast indefinitely, making metal type economical despite the capital cost of machinery. However, metal bars were heavy, fragile, and prone to bending if dropped or mishandled. Spaces and punctuation had to be carefully composed within the line; a missing space or broken character in the bar meant the entire line was waste.
The term "type bar" can cause confusion with the lever or carriage that holds type in some older presses, but in composition machinery, it refers strictly to the cast line itself. By the 1970s and 1980s, offset printing and digital composition rendered hot-metal lines obsolete, and type bars disappeared from most production workflows. Printers who still maintain letterpress equipment for specialty work understand type bars as the backbone of that technology.