Slowinski served as professor of painting at the Kansas City Art Institute. He received a Certificate of Art in painting from the School of Art Institute of Chicago in 1954. Thirty years later he had a twenty-five year retrospective at the Sheldon Memorial Gallery of Art at the University of Nebraska in Lincoln. His works are a part of major museum collections such as the Albright-Knox Museum in Buffalo, New York, and the Nelson-Atkins Museum of Art in Kansas City, Missouri. He has exhibited in numerous solo and group exhibitions throughout the United States and Japan. He was the recipient of a Fulbright Advanced Grant to Japan and taught at Indiana University before coming to Kansas City.