A Letraset design by Michael Neugebauer (not his father Friedrich, as ITC incorrectly attributes it).
Berthold had it as Circulus (1972). Digitized by URW as Circle.
Contributed by Benjamin Brandt
Contributed by Garrison Martin
Photo(s) by Henk Gianotten on Flickr.
Contributed by Rob Hudson
Photo(s) by Buro Destruct on Flickr.