How to halation: why dark mode text needs adjustments
- Step 1Understand the perception — Eye lens scatters light when high-contrast edges are present. Light text on dark background creates more scatter than dark on light. Result: light strokes appear thicker than dark strokes of the same width.
- Step 2Compensate with weight reduction — Reduce weight class by 50–100 in dark mode. The same character at weight 350 dark feels equivalent to weight 400 light. Variable fonts enable precise tuning.
- Step 3Add spacing for readability — Slightly wider letter-spacing (0.01em) prevents adjacent characters from blooming into each other. Slightly looser line-height (1.55 vs 1.5) prevents row-bleed on OLED. Subtle but cumulatively important.
Frequently asked questions
Is halation worse on OLED?+
Yes — OLED's perfect blacks and high-contrast pixel edges intensify the effect. LCD displays with backlighting don't show halation as strongly because the dark pixels still emit some light. Adjustments matter most on OLED-equipped devices.
Does monitor brightness matter?+
Yes — at high brightness, halation dominates; at low brightness it's invisible. Auto-brightness on phones means typography appears different at sunset vs in a dark room. Compensation handles the worst case.
Are there other typographic dark-mode adjustments?+
Yes — reduce contrast slightly (off-white #EAEAEA vs pure white #FFFFFF), avoid pure black backgrounds (use #181818 vs #000000). Both reduce halation. Combined with weight/spacing adjustments, dark mode reads like light mode.
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