A faculty member at Chicago's School of the Art Institute walked up recently to a group of students clustered around their professor, Sonia Sheridan. Seeing them studying paper they had just taken from a copying machine, he asked, "Is it art yet?"

Answers vary. There are skeptics who say photocopy machines are as likely to produce popcorn as art. But New York's Museum of Modern Art has exhibited works produced by the machines. The Guggenheim Foundation granted a fellowship to study their creative use. Reputable schools like MIT and the University of Minnesota recognize photocopy art as a bona fide field. Anxious not to trivialize the form she largely developed, Sheridan calls it "generative art."

Sheridan's classroom is equipped with 50 machines, some of them no longer even manufactured—from a primitive Haloid-Xerox copier and instant print cameras to the newest color reproducers. "Equipment isn't art," she tells her students, "but the people who use it make it art. Think of the machines as another big pencil."

A teacher for 25 years—of kinder-garten, high school French and college art—the high-spirited Sheridan, 52, declines the honor of having invented creative copying: "Some secretary back in the '50s probably made the first generative art when she copied her hand." It was Sheridan, however, who was inspired to explore the possibilities of the machines in 1968 when students asked her help in making antiwar posters.

In 1969 she worked with engineers at 3M, studying their color machines. Douglas Dubvig, director of 3M's chemical research lab, admits, "I didn't believe there was artistic value in the equipment. Sonia opened our eyes."

The next year the School of the Art Institute set up the nation's first copy machine art course. Flowers and parts of the body were copied and re-copied in varying colors. While Sonia concedes that "in the beginning nobody understood what in the hell I was doing," such astute culture mavens as her dean, Roger Gilmore, now says, "This type of art will ultimately have a recognized place in the art world." On the other hand, as late as 1974, the New York Times dismissed her and colleague Keith Smith's Museum of Modern Art show as "an artistic flop." (It included a 47-foot-high naked man pieced together from enlarged copies of parts of the body.)

Sheridan often takes her work home to the cluttered Evanston apartment she shares with her husband, Jim, 54, a Northwestern University professor of Chinese history. Their son, Jamy, 28, lives in California. Because Jim often cooks dinner, Sonia made him an apron with her own face (applied by heat transfer) on the pocket—"so I can keep an eye on him."

Sheridan encourages her students to try out any of their ideas on the machines, however wild—even their own bare bottoms. Teacher herself is a favorite model, although the joke at the school about the irrepressible Sonia is that nobody could really duplicate her.