Axis / Stress

The imaginary line connecting the thinnest parts of a curved
Stroke
, indicating the angle at which contrast is distributed within a letterform. The effect is most easily observed in the letter o. A diagonal stress (tilted to the left) reflects the natural angle of a broad-nib pen and is characteristic of
Old Style Serif
Typeface
; a vertical (upright) stress indicates the rationalized construction of
Transitional Serif
and
Modern Serif
designs. Stress angle is one of the primary diagnostic criteria for placing a typeface within the historical
Serif
progression from old style through transitional to modern.