Here’s an interesting typeface from relatively recent history. Beowolf is an experimental typeface that’s an exception to the rule of standardization in typography. Each printed letter’s outline is randomized, making it different from others of the same letter.
PostScript allows the designer to build a font program that modifies, changes or switches letterforms. Beowolf is the first font (1989) we build with a randomisation routine. All points on the contour of a (fairly) normal typeface are given a space in which they can freely move. So instead of each letter having one fixed form, the shapes move and wobble. Every single letter this typeface will print will be unique. If characters are repeated in a text they will have different shapes.
It’s an interesting example of intentional irregularity in a digital typeface. One of the biggest differences between graffiti and typography is the standardization of the letters. While Beowolf’s irregularity is computer generated rather than handwritten/painted, it is an important exception that crosses one of the usual boundaries between graffiti and typography.