In 1911 Graeser enrolled at the course for furniture and interior design at the Königliche Kunstgewerbeschule (Royal School of Arts and Crafts) in Stuttgart. On the side he made drawings and paintings that veered towards abstraction. In 1918 he was accepted into the Deutsche Werkbund (a German association of artists, designers and industrialists) and took part in the exhibitions of the association. In 1933 Graeser returned to Switzerland and four years later he turned his full attention to Geometric Abstraction. He made systematic paintings, using few but variantly manipulated geometric elements and strikingly bright colours. Since 1950 Graeser, together with Bill, Loewenberg and Lohse, has been considered one of the leading representatives of Concrete Art in Switzerland.