Verner Panton (1926 – 1998) of Denmark created innovative, futuristic designs in vibrant colors with a variety of materials, especially plastic. Though his style was very "1960s," he regained popularity at the end of the 20th century. As of 2004, his most of his well-known furniture models are still in production. Already an experienced artist, Panton studied architecture at the Royal Danish Academy of Art in Copenhagen, graduating in 1951. During the first two years of his career, 1950–1952, he worked at the architectural practice of Arne Jacobsen, another Danish architect and furniture designer. Panton started his own design and architectural office and became well known for his innovative architectural proposals, including a collapsible house (1955), the Cardboard House and the Plastic House (1960). In the mid-1950's, Panton converted a Volkswagen bus into a mobile studio and travelled across Europe. He returned to Denmark in 1958 full of unconventional ideas, one of which evolved into the iconic Heart Cone Chair. In 1960 Panton was the designer of the very first single-form injection-molded plastic chair. The Stacking chair or S chair, became his most famous design and was mass-produced.