Born in Dresden as Conrad Felix Müller, he chose Felixmüller as his nom d'artiste.

[1] He published many woodcuts and drawings in left-wing magazines, and remained a prolific printmaker throughout his career.

[2] He was a close friend of the composer Clemens Braun of whom he produced a number of portraits and a woodcut depicting him on his deathbed.

In tribute following the news of Rheiner's death, Felixmüller's painting 'Der Tod des Dichters Walter Rheiner'pays homage to his deceased friend.

[6] He wrote in 1929:It has become increasingly clear to me that the only necessary goal is to depict the direct, simple life which one has lived oneself, also involving the design of colour as painting—in the manner in which it was cultivated by the Old Masters for centuries, until Impressionism and Expressionism, infected by the technical and industrial delusions of grandeur, rejected every affinity for tradition, ability and results, committing harakiri.