An imaginary line drawn from top to bottom of a glyph (letter or character of type) bisecting the upper and lower strokes is the axis. For typefaces that exhibit changes in the thickness of curved strokes, the inclination of the axis of the lowercase o is used to measure the angle of stress. A completely vertical axis indicates a design with an angle of 0 or vertical stress. When the axis leans to the left or right the design has angled or diagonal (positive or negative) stress. Early styles of typefaces generally shared similar axis or stress angles.
The axis or design axis is also an adjustable attribute of some fonts. Adjusting the design axis results in variations in the weight, width, size, and other features of the typeface.
Also Known As: stress | angle of stress | design axis
Common Misspellings: axes (unless the plural of axis is intended)
Examples: Old Style fonts, based on ancient Roman inscriptions, typically have a slight to strong left-leaning or negative axis while Transitional styles that evolved later had less stress or a closer to vertical axis.