Display titles (xl–3xl) use very tight line-heights (1.05–1.15) and negative tracking (-0.02 to -0.025em) for hero sections. Standard titles use slightly more relaxed values (1.2–1.35 line-height) for general use.
Paragraphs use neutral letter-spacing and line-height of 1.5–1.6 for comfortable extended reading. Research shows 150% line height improves reading accuracy by up to 20%.
Labels use slightly positive letter-spacing (+0.01 to +0.02em) to improve legibility at small sizes. Tighter line-heights (1.25–1.35) work well for single-line UI elements.