John Clark studied in the Glasgow School of Art, Department of Murals and Stained Glass where he graduated in 1980 as BA, followed by a further study in GSA to achieve a MA degree. He was a lecturer in stained glass until 1985. Since 1985, he has been a freelance stained glass artist. He established a studio in Scotland and worked there until 1990. Since 1990, he has made all of his work in the Derix Studios in Germany. He was awarded an Honorary Doctorate from the University of Paisley in 2003.