I remember doing this by accident in an email back in the days in which all interactions with a computer were in monospace (on a 80x24 terminal screen). Fiddlin

I remember doing this by accident in an email back in the days in which all interactions with a computer were in monospace (on a 80x24 terminal screen). Fiddling with margins to make it work is kind of cheating (and curiously, it seems to be easier with narrower line lengths than wider ones). Doing it for an extended period of time with consistent margins is a real challenge.