canon

In metal type foundries, a canon was a cast type body measuring 48 points in height, making it one of the largest sizes available in traditional letterpress printing. The name derives from its original use: printing the canons of the church, ecclesiastical laws and decrees that demanded prominence on the page. A 48-point body is roughly 2/3 of an inch tall, suitable for display work, title pages, and proclamations where readability across distance mattered.

The term belongs to a hierarchy of type sizes standardized in the 19th century. Below canon sat smaller display sizes like pica (12 point) and great primer (18 point); above it, only double pica (24 point) and occasionally larger custom castings appeared. Different foundries sometimes varied their canon slightly, but 48 point became the accepted standard. The size was cast on a metal body with proper bearing, allowing it to sit alongside smaller types in mixed composition, though canon was rarely combined with body text.

Canon fell into disuse during the 20th century as metal type gave way to photosetting and digital composition. The terminology persists in foundry archives and in the vocabulary of letterpress practitioners, but the physical objects are now scarce and sought by printers who still work with metal. Modern digital type designers sometimes offer fonts scaled to historical point sizes, including canon, though the practical relationship between point size and physical printed output differs between metal and screen.

The size proved expensive to cast and required significant press force to print cleanly. Wear on the face was rapid; a canon character would show battered serifs after moderate use. The weight of a full font in canon made it cumbersome to handle and store, another reason many smaller foundries never stocked complete ranges. By contrast, pica and great primer sizes were economical to produce and maintain, so they dominated jobbing work.