Paul Klee

Context: In 1919, Klee applied for a teaching post at the Academy of Art in Stuttgart. This attempt failed but he had a major success in securing a three-year contract (with a minimum annual income) with dealer Hans Goltz, whose influential gallery gave Klee major exposure, and some commercial success. A retrospective of over 300 works in 1920 was also notable.  Klee taught at the Bauhaus from January 1921 to April 1931. He was a "Form" master in the bookbinding, stained glass, and mural painting workshops and was provided with two studios. In 1922, Kandinsky joined the staff and resumed his friendship with Klee. Later that year the first Bauhaus exhibition and festival was held, for which Klee created several of the advertising materials. Klee welcomed that there were many conflicting theories and opinions within the Bauhaus: "I also approve of these forces competing one with the other if the result is achievement."  Klee was also a member of Die Blaue Vier (The Blue Four), with Kandinsky, Lyonel Feininger, and Alexej von Jawlensky; formed in 1923, they lectured and exhibited together in the USA in 1925. That same year, Klee had his first exhibits in Paris, and he became a hit with the French Surrealists. Klee visited Egypt in 1928, which impressed him less than Tunisia. In 1929, the first major monograph on Klee's work was published, written by Will Grohmann.  Klee also taught at the Dusseldorf Academy from 1931 to 1933, and was singled out by a Nazi newspaper, "Then that great fellow Klee comes onto the scene, already famed as a Bauhaus teacher in Dessau. He tells everyone he's a thoroughbred Arab, but he's a typical Galician Jew." His home was searched by the Gestapo and he was fired from his job. His self-portrait Struck from the List (1933) commemorates the sad occasion. In 1933-4, Klee had shows in London and Paris, and finally met Pablo Picasso, whom he greatly admired. The Klee family emigrated to Switzerland in late 1933.  Klee was at the peak of his creative output. His Ad Parnassum (1932) is considered his masterpiece and the best example of his pointillist style; it is also one of his largest, most finely worked paintings. He produced nearly 500 works in 1933 during his last year in Germany. However, in 1933, Klee began experiencing the symptoms of what was diagnosed as scleroderma after his death. The progression of his fatal disease, which made swallowing very difficult, can be followed through the art he created in his last years. His output in 1936 was only 25 pictures. In the later 1930s, his health recovered somewhat and he was encouraged by a visit from Kandinsky and Picasso. Klee's simpler and larger designs enabled him to keep up his output in his final years, and in 1939 he created over 1,200 works, a career high for one year. He used heavier lines and mainly geometric forms with fewer but larger blocks of color. His varied color palettes, some with bright colors and others sober, perhaps reflected his alternating moods of optimism and pessimism. Back in Germany in 1937, seventeen of Klee's pictures were included in an exhibition of "Degenerate art" and 102 of his works in public collections were seized by the Nazis. CANNOTANSWER

Question: Besides heavier lines and geometric forms, what else makes Paul Klee's work from the mature period recognizable?
Answer: His varied color palettes, some with bright colors and others sober,