Typographic Modulation

Systematic variation of a typeface's visual parameters — weight, width, slant, size, colour, letter spacing, baseline shift, opacity — to carry information beyond the literal words, typically driven by an external signal such as speech pitch, loudness, emotional arousal, or emphasis. Typographic modulation underlies expressive and affective captioning: per-word font weight can track speech intensity, colour can encode valence, and font size can signal arousal. Variable fonts make modulation computationally cheap at render time, but designers must balance expressive contrast against readability, accessibility, and user cognitive load.