Designer Fredrick R. Brennan was disgusted by terrible fake typewriter props in movies and TV, obviously created by people who either haven’t seen a typewriter in years or maybe ever:
The main problem is that an analog typewriter is incapable of producing the same output every time. Even the IBM Selectric, one of the most mechanically sophisticated typewriters ever produced, is incapable of doing this. However, most people are not trying to imitate an IBM Selectric; instead they are trying to imitate much older typewriters such as the Underwood №5.
Our computers are too precise. Typewriter fonts make the same grungy letterforms every single time. Real typewriters were imprecise mechanical devices whose output varied based on the force imparted by the typist, the ink on the ribbon, and the condition of the type head itself.
Brennan’s solution was to create an OpenType font that includes nine variations on every letter, to make the output seem less consistent, and thus more realistic.
This is great. You can download the fonts. Most people won’t need them, but art directors and prop masters please take note!