Three weights (Naught, One, and Two) were released in 1970 by Face [Reichardt]. Other styles followed, including Outline, Heavy Outline, Rimmed (contour), and Condensed, which is nearly identical to Aral and its offshoots. Formula One was also produced by Letraset in 1973, [Modern Publicity] with a “Face Photosetting” credit.
Not to be confused with Formula (Pangram Pangram, 2018/2022).