Vallien studied at the Gothenburg School of Art and Design and went on to work as a designer for the Kosta Boda glass company. He was one of the first designers to use the molding technique in glasswork, which enabled him to create large, complex pieces.
Over the course of his career, Vallien has received numerous awards and honors for his work, including the Grand Prix at the Kanazawa International Glass Biennale in 1981. He also exhibited his work in galleries and museums around the world, including the Musée des Arts Décoratifs in Paris, the Museum of Modern Art in New York and the Victoria and Albert Museum in London.
Vallien is considered one of Sweden's most important designers of his generation, and has influenced many artists and designers around the world. He passed away on April 3, 2021, leaving behind him an important legacy in the world of design and glass.