Karl was a German-born artist who grew up in Philadelphia. Since his childhood, Karl was fascinated by frogs, birds, insects, crystals and shells. He used to watch his father working as a fine jeweler which got him interested in metal. He started his art career at age of 23. He was an industrial designer who served in the World War II. Although self-taught, Karl held teaching positions at Tyler School of Art at Temple University and at Moore and Swarthmore colleges. He operated a metal arts studio, designing and making contemporary metal furniture and ecclesiastical items, such as lighting fixtures, altar railings, architectural sculpture, ornamental panels, screens, and lamps.
Karl brought new life to metal that had been discarded, whether from Bethlehem Steel, shipwrecks, or from his favorite scrapyard. He fused natural materials with manmade and juxtaposes smooth surfaces with rough and pitted ones to form organic shapes. Karl created a drama of contradiction, playing thick against thin, flexible against inflexible.
In 1959 he had a solo show at the Delaware Museum of Art and in 1963 showed 52 engravings at the Philadelphia Print Club. Karl’s sculpture was put on hold as he raised a family and pursued other business interests, but the interruption fueled his drive and since 1985 more than 400 pieces have come out of his Easton, Pennsylvania, studio.
His work has been shown at the Museum of Modern Art New York, Pennsylvania Academy of Fine Arts, Philadelphia Museum of Art, Corcoran Gallery of Art, La Jolla Museum of Contemporary Art, Hunterdon Art Museum, Allentown Art Museum, James A. Michener Art Museum and Grounds for Sculpture, among many others. He has been a mentor to the Easton artists community, and the Karl Stirner Arts Trail was named in his honor.