Klarwein was born in Hamburg, Germany. His family was of Jewish origin and fled to the British Mandate of Palestine when he was two years old, after the rise of Nazi Germany. In 1948 when the territory became Israel, his family traveled to Paris. There Mati studied with Fernand Léger, after attending the École des Beaux-Arts. Klarwein traveled south to Saint-Tropez and met Ernst Fuchs, who would have a profound influence on him. Leaving France in the 1950s, Klarwein traveled widely and lived in many different countries, including Tibet, India, Bali, North Africa, Turkey, Europe and the Americas. He settled in New York City in the early 1960s for a while, meeting Jimi Hendrix and many other artists.
Much of Klarwein’s most famous work is inspired by surrealism and pop culture, but also reflects his interest in non-Western deities, symbolism, and landscapes. The alleged connection between Klarwein and the so-called psychedelic art of the period is not entirely unfounded, as he has detailed his experience with LSD in his 1988 book Collected Works; however, Klarwein also explains that drugs were never his prime inspirational source, and in one interview, denies their influence entirely. His extensive travels and wide interests (notwithstanding the fact that his style had fully developed before the “psychedelic era”) are further support of his claims. Klarwein claims that his friend Timothy Leary once told him, based on the character of his paintings, that Klarwein “didn’t need psychedelics”