Frida Kahlo and Diego Rivera
Kahlo’s auction record— nearly double Rivera’s— suggests that her work is more highly valued. But the discrepancy stems from Kahlo’s relatively minuscule output, says Virgilio Garza, the head of Latin American Paintings at Christie’s New York, and the fact that both markets are dampened by Mexican patrimony laws, which prevent work by certain “national treasures” from being sold internationally.

Emmy Lou Packard, Courtesy Emmy Lou Packard papers, 1900–90, Archives of American Art, Smithsonian Institute