Cline had no formal art training, but art was a major influence in his life while growing up: His father was an art professor at the University of Colorado who often invited artists from around the world to give presentations to his class. "I was always around art, so it was kind of like second nature," Cline says. "They taught me a few fundamental things but other than that I was self-taught." Seeking influence from even the most famous of artists, like Salvador Dali, to some of his father's graduate students, he learned from their style and developed his own. He was approached by the principals of Stanley Lake and Arvada West high schools, who had seen his work and wanted Cline to do something for them. After that, "I became so busy that I felt like I needed to quit my job," says Cline. "My boss told me, Mark you need to follow your bliss," so I went for it. He also participates in the Street Chalk movement and street art has recently developed into a more respected branch of the fine arts, which has helped, "The chalk artists are a big community," Cline says. "We do anything for each other and there is a great sense of camaraderie. His favorite style of painting is surrealism but he usually saves that for his canvas rather than the murals.