Setting the default size to 300 should strike every web developer as questionable—outside Apple’s ecosystem (where it’s more likely to pan out), it’s just narro

Setting the default size to 300 should strike every web developer as questionable—outside Apple’s ecosystem (where it’s more likely to pan out), it’s just narrowly tolerable in some fonts, but in most it’s outright painful on (as probably the most extreme example) Windows with a low-DPI screen. For typical meanings of 300 weight, I’d generally say flat-out don’t use it below 20px. 200, on the other hand, is unquestionably bad for body-sized type, and no one sane will disagree. (Useful related research work here: Accessible Perceptual Contrast Algorithm, APCA, is being developed to replace the old and terrible contrast ratio calculations used in WCAG; and it takes font weight into account! https://www.myndex.com/APCA/ https://www.myndex.com/APCA/ lets you explore this and see it visually. I said a minimum of 20px for 300 weight; APCA will tend to be a little more lenient than me, and declares a minimum acceptable font size of 17px for 300 black on white.)