The type gauge is a ruler graduated in typographic units, such as the Didot point or the pica point, as well as centimeters. It is used to measure the size of a typeface, the leading or the line length of a printed document.
Where to see it
The type gauge is part of the historic toolkit of typesetters, layout artists and proofreaders. Today it is mostly found as a transparent ruler printed with letters at different sizes, placed on a page to identify the size of a text.
Why this detail matters
The type gauge remains a valuable tool for working with print:
- It quickly identifies the point size and leading of a printed text, for example to reproduce an existing layout;
- It helps check that a printed document matches the settings planned in the file;
- It is a reminder that typography has its own units of measurement, distinct from metric units.
Related term
The em is one of the reference typographic units, equal to the font size.