An interesting thread on MapHist about painting on maps — i.e., using a map like a canvas — yielded links to the following artists.
Suzanne Howe-Stevens: “Using maps as a background or frame allows her to emphasize the borders that exist between water and land. Those spaces that we love so much are disappearing; this is often reflected in the water scene’s drift into the map area.” Her works are subtle; you can’t really see the map backgrounds unless you examine them in close detail.
Brenda Schwartz-Yeager “paints both conventional watercolors and watercolor images on preserved navigational charts, adding personality to those images, each chart telling its own story.” Much more traditional work, with nautical themes on nautical charts, for example. Sample at right.