His Dark Material

The greatest works of art are inevitably turned into kitsch, their fame exploited to sell the most banal products. Guernica adorns T shirts, the Mona Lisa is woven into welcome mats, Sunflowers brightens up your morning coffee mug. Edward Hopper's Nighthawks has suffered the same fate. Prints of the iconic 1942 painting of a gloomy diner have shown up in several generations of American college dorms — there's even a mouse pad. Has reproduction robbed the image of its morose power and reduced Hopper, one of America's greatest artists, to the ranks of the one-hit wonders?

Not on...