San Francisco fonts are dynamic

One of the great features of San Francisco is the way it optimizes the typeface dynamically. The system will automatically switch the Display/Text fonts according to the text size. Specifically, 20pt is the boundary.

Designers and engineers don’t have to care about which font to use. Just set the system fonts to UILabel for example, and then the system will give you an appropriate typeface for you.

What have impressed me about San Francisco fonts is the way colons (:) are displayed. Basically, a colon will be placed right above the baseline, so it’s not vertically centered if it is placed between numbers. San Francisco fonts, on the other hand, will make it vertically centered automatically.