Glossary Term Definition
The degree of variation between the thick and thin strokes of a letterform; high-contrast faces have dramatic variation, while low-contrast faces have relatively uniform stroke width.
Definition
The degree of variation between the thick and thin strokes of a letterform. High-contrast faces, such as Bodoni, have dramatic variation between thick and thin. Low-contrast faces, such as Futura, have relatively uniform stroke width. Contrast is one of the defining attributes of typographic classification.
Source
No access — Robert Bringhurst — p. 323:
The degree of variation between the thick and thin strokes of a letterform.