Oscar Reutersvärd was a Swedish visual artist and sculptor. He began his studies as a student with Otto G. Carlsund in Stockholm, then studied at Otte Sköld’s Painting School from 1935-36, and with Fernand Léger in Paris between 1950 and 1951. Reutersvärd developed various kinds of optical illusions in his works, creating “impossible figures”. In 1934, he created the first “impossible triangle”, using geometric forms that cannot exist, as they violate the basic laws of trigonometry and perspective. Reutersvärd’s work can be seen at Moderna Museet in Stockholm, Centre Pompidou in Paris, Musée des Beaux-Arts in Rouen and the National Gallery in Oslo.