Obel Mono Masked: A typeface that keeps a secret

    > A font is a small program

    > We think of a font as a set of drawings. It’s also a set of rules. Each time text appears, a piece of your system called a shaper reads the font’s rules and may swap one glyph for another. It’s how a font joins f and i into a ligature.

    > Nothing says a rule has to be about typography.