Miller's mother died when he was two, after which his family moved to Cleveland, where he attended Hough Elementary School and later Shaker Heights High School. He then enrolled in classes at the Cleveland Museum of Art following this with courses at the Cleveland School of Art where he studied enameling with Kenneth F. Bates. In 1936 he enrolled in the Cleveland School of Art's industrial design program. Inspired by the silver jewellery of another student, Frederick A. Miller, John Paul set out to learn the techniques demanded by working with silver. He soon started creating rings and brooches using classical music and the natural world as inspiration. Some of his teachers greatly influenced his work: Kay Dorn Cass, Paul Travis, Walter Sinz, Carl Gaertner and Viktor Schreckengost. John Paul later shared a studio and home with Fred Miller, his wife Mary and two children. After the death of Mary Miller in 1998 and Fred Miller in 2000, John Paul Miller continued living in the house, located south of Cleveland. On his graduation in 1940, John Paul taught at the Cleveland School of Art for a year. His tour of duty with the Army at Fort Knox in Kentucky found him illustrating manuals on tank tactics. Shortly after resuming his position at the School in 1946 he discovered a document by an archaeologist at the American Academy in Rome on the ancient technique of granulation, a process which involves fixing minute gold beads to a gold surface without using any form of solder, thereby creating a finely textured coruscating surface. The paper was sufficient to guide Miller in the right direction - gold in the presence of copper lowers the melting point of both metals. By allowing copper to oxidise on the surface of gold globules, Miller rediscovered the ancient process making possible the fashioning of intricate designs. His work drew great attention at the Designer Craftsman U.S.A. show of 1953, displays at the Art Institute of Chicago in 1957, New York’s Museum of Contemporary Crafts in 1964, international acclaim at the Brussels World's Fair, the Objects USA traveling exhibition of 1970, the Museum Bellerive in Zurich, the Vatican Exhibition of American Crafts, and the Great Jewelry of the Ages exhibition at the Victoria and Albert Museum in London. His work is on permanent display at the Cleveland Museum of Art, the Renwick Gallery of the Smithsonian Institution, the Museum of Contemporary Crafts in New York City, the Minnesota Museum of American Art in St. Paul, Vassar College, Yale University, and the Fleischman Collection. Despite all this exposure, fame arrived belatedly for Miller at 92 years of age, when curator Stephen Harrison arranged a 2010 retrospective of his work at the Cleveland Museum of Art. Miller was an experienced hiker and outdoorsman who enjoyed hiking trips in the Rocky Mountains and the Tetons.
