In the manufacture of
metal type used in
letterpress printing
Letterpress printing is a technique of relief printing for producing many copies by repeated direct impression of an inked, raised surface against individual sheets of paper or a continuous roll of paper. A worker composes and locks movable t ...
, a matrix (from the Latin meaning ''womb'' or ''a female breeding animal'') is the mould used to cast a letter, known as a
sort. Matrices for printing types were made of
copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
.
However, in
printmaking
Printmaking is the process of creating work of art, artworks by printing, normally on paper, but also on fabric, wood, metal, and other surfaces. "Traditional printmaking" normally covers only the process of creating prints using a hand proces ...
the matrix is whatever is used, with ink, to hold the image that makes up the print, whether a plate in
etching
Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other type ...
and
engraving
Engraving is the practice of incising a design on a hard, usually flat surface by cutting grooves into it with a Burin (engraving), burin. The result may be a decorated object in itself, as when silver, gold, steel, or Glass engraving, glass ar ...
or a woodblock in
woodcut.
Description
In letterpress or "cold metal" typesetting, used from the beginning of printing to the late nineteenth century, the matrix of one letter is inserted into the bottom of an adjustable-width
hand mould, the mould is locked and molten
type metal
In printing, type metal refers to the metal alloys used in traditional Movable type, typefounding and hot metal typesetting. Historically, type metal was an alloy of lead, tin and antimony in different proportions depending on the application, b ...
is poured into a straight-sided vertical cavity above the matrix. When the metal has cooled and solidified the mould is unlocked and the newly cast metal sort is removed. The matrix can then be reused to produce more copies of the sort.
[Meggs, Philip B. ''A History of Graphic Design.'' John Wiley & Sons, Inc. 1998. (pp 58–69) ] The sorts could then be cleaned up and sent to the printer. In a low-pressure hand mould matrices are long-lasting and so could be used many times.

In the
hot metal typesetting
In printing and typography, hot metal typesetting (also called mechanical typesetting, hot lead typesetting, hot metal, and hot type) is a technology for typesetting text in letterpress printing. This method injects molten type metal into a mo ...
systems of the later years of metal type printing, from the late nineteenth century onwards, new type is cast for each job under the control of a keyboard. The matrix or mats for a complete font are loaded into a matrix-case and inserted into a casting machine, which casts the required sorts (or, in a Linotype machine, a solid block for each line) for a
page
Page most commonly refers to:
* Page (paper), one side of a leaf of paper, as in a book
Page, PAGE, pages, or paging may also refer to:
Roles
* Page (assistance occupation), a professional occupation
* Page (servant), traditionally a young m ...
composition automatically, often from a paper reel.
Manufacture
The standard method to make a matrix was to drive a
steel punch in the shape of the type to be made into soft copper.
The matrix could then be cleaned up and cut down to the width of the letter to be cast: this is called "justification" and sets the width of the letter when cast. A matrix that has not yet been justified is called a "strike". Adjustment of the matrix had to be done very carefully to ensure even flow of letters on the page.
Large typefaces, or wide designs such as emblems or medallions, were never very easily produced by punching since it was hard to drive large punches evenly. Early alternative methods used included printing from woodblocks, 'dabbing', where wood-blocks were punched into metal softened by heating, or carefully casting type or matrices in moulds made of softer materials than copper such as sand, clay, or punched lead.
One solution to the problem in the early nineteenth century was William Caslon IV's riveted "Sanspareil" matrices formed by cut-out from layered sheets. The problem was ultimately solved in the mid-nineteenth century by new technologies, electrotyping and pantograph engraving, the latter both for
wood type
In letterpress printing, wood type is movable type made out of wood. First used in China for printing body text, wood type became popular during the nineteenth century for making large display typefaces for printing posters, because it was lig ...
and then for matrices.
From the nineteenth century additional technologies arrived to make matrices. The first was
electrotyping
Electrotyping (also galvanoplasty) is a chemical method for forming metal parts that exactly reproduce a model. The method was invented by a Prussian engineer Moritz von Jacobi in Russia in 1838, and was immediately adopted for applications in ...
from the 1840s, which forms a copper matrix around a pattern letter by
electrodeposition of copper. The advantage of electrotyping was that the pattern letter did not have to be out of hard steel, so it could be cut in soft lead alloy much faster than a punch could. This allowed an explosion in the number of
display typefaces available.
It also allowed printers to form matrices for types for which they did not have matrices, or duplicate matrices when they had no punches, and accordingly was less honourably used to pirate typefaces from other foundries.
The technology was most commonly used for larger and more esoteric
display typefaces, with punched matrices preferred for body text types.
An additional technology from the 1880s was the direct engraving of punches (or matrices, especially with larger fonts) using a
pantograph
A pantograph (, from their original use for copying writing) is a Linkage (mechanical), mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a se ...
cutting machine, controlled by replicating hand movements at a smaller size.
Duplexing

A duplexed matrix with two sites for casting letters was common on Linotype machines. By switching the position of the matrices in the machine it was easy to switch between casting two styles in the same line, the characters of which would have identical width.
A common combination was regular and italic for printing
body text, or regular and bold as with
Metro, but Linotype also offered more unusual combinations, such as a serif text face duplexed with a bold sans-serif for emphasis.
See also
*
Font
In metal typesetting, a font is a particular size, weight and style of a ''typeface'', defined as the set of fonts that share an overall design.
For instance, the typeface Bauer Bodoni (shown in the figure) includes fonts " Roman" (or "regul ...
*
History of western typography
*
Digital print matrix
References
{{Letterpress
Typography
Printing