Among his students the so-called "Hölzel circle" developed, including Oskar Schlemmer, Willi Baumeister, Max Ackermann, Alf Bayrle and Johannes Itten.
In 1950 some former members of the Deutscher Künstlerbund – Karl Hofer, Willi Baumeister, Karl Hartung and Karl Schmidt-Rottluff – re-established it.
After "Cercle et Carré", he also became a member of the artist association "Abstraction-Création" in Paris.
Willi Baumeister | Willi Forst | Willi Sänger | Willi Plett | Willi Lippens | Willi Williams | Willi van Ooyen | Willi Hennig | Willi Braun | Chilli Willi and the Red Hot Peppers | 40. Fallschirmjägerbataillon Willi Sänger | Willi Weber | Willi Veller | Willi Stöhr | Willi Reschke | Willi Oberbeck | Willi Ninja | Willi Kronhardt | Willi Hennig Society | Willi Gerdau | Willi Frommelt | Willi Fels | Willi Arlt | Oil portrait painting of ''Friedrich Christian Baumeister |
Stahl belonged to what could be called the 'mid-generation' of German artists, born around or shortly after the turn of the century, like Willi Baumeister, Fritz Winter, Ernst Wilhelm Nay, and Theodor Werner.
Along with Schlemmer's diary, his private letters to Otto Meyer and Willi Baumeister have given valuable insight on what happened at the Bauhaus; especially his writings of how the staff and students responded to the many changes and developments at the school.