Typographic units are the units of measurement used in typography or typesetting. Traditional typometry units are different from familiar metric units because they were established in the early days of printing. Though most printing is digital now, the old terms and units have persisted.

Didot is the name of a family of French printers, punch-cutters and publishers. Through its achievements and advancements in printing, publishing and typography, the family has lent its name to typographic measurements developed by François-Ambroise Didot and the Didot typeface developed by Firmin Didot. The Didot company of France was ultimately incorporated into the modern CPI printing group.