The Linotype machine needed matrices. And that is something special. The shape and the teeth of the matrices has never changed. She ran from the first to the last machine in the magazines and even all competitors used the same matrices and sets of teeth, so as to always be replaceable. Even later in the transition to other technologies the Linotype customers demanded, that the type should look exactly like the hot metal version. One reason that there are
typefaces, which have in the Roman version and the Italic and Bold using the same width of the letters.