I paired a geometric sans-serif with a condensed display font for an educational blog. The combination looked sharp in the design file. Reading more than three paragraphs gave users headaches.
The condensed font I chose for body text had a Flesch Reading Ease score of 28, classified as very difficult to read. Average reading speed dropped from 250 words per minute to 180 words per minute based on user testing.
Accessibility audit revealed the problems
The geometric font had identical lowercase L and uppercase I characters. Students confused them constantly in code examples and technical content. The condensed display font failed WCAG AAA standards at any size below 18px.
Users with dyslexia reported the text was nearly impossible to parse. The tight letter spacing and unusual character shapes added cognitive load to every sentence.
System fonts performed better in every metric
Switching to system font stacks with proper fallbacks improved reading speed by 38%. Comprehension test scores increased from 64% to 87%. Time spent on educational content went up because reading became effortless instead of a chore.
Your font choices should be invisible. If users notice your typography, you've failed. System fonts like San Francisco, Segoe UI, and Roboto are optimized for screen reading. They're boring because they work.