Alfaro Siqueiros, José Clemente Orozco, and Fernando Leal. It is the most studied part of Mexico's art history. All were artists trained in classical European techniques and many of their early works are imitations of then-fashionable European paintings styles, some of which were adapted to Mexican themes. The political situation in Mexico from the 1920s to 1950s and the influence of Dr. Atl prompted these artists to break with European traditions, using bold indigenous images, much color, and depictions of human activity, especially of the masses, in contrast to the solemn and detached art of Europe. Preferred mediums generally excluded traditional canvases and church porticos and instead were the large, then-undecorated walls of Mexico's government buildings. The main goal in many of these paintings was the glorification of Mexico's pre-Hispanic past as a definition of Mexican identity. They had success in both Mexico and the United States, which brought them fame and wealth as well as Mexican and American students. These muralists revived the fresco technique for their mural work, although Siqueiros moved to industrial techniques and materials such as the application of pyroxilin, a commercial enamel used for airplanes and automobiles. One of Rivera's earliest mural efforts emblazoned the courtyard of the Ministry of Education with a series of dancing tehuanas (natives of Tehuantepec in southern Mexico). This four-year project went on to incorporate other contemporary indigenous themes, and it eventually encompassed 124 frescoes that extended three stories high and two city blocks long. The Abelardo Rodriguez Market was painted in 1933 by students of Diego Rivera, one of whom was Isamu Noguchi. Another important figure of this time period was Frida Kahlo, the wife of Diego Rivera. While she painted canvases instead of murals, she is still considered part of the Mexican Modernist School as her work emphasized Mexican folk culture and colors. Kahlo's self-portraits during the 1930s and 40s were in stark contrast to the lavish murals artists like her husband were creating at the time. Having suffered a crippling bus accident earlier in her teenage life, she began to challenge Mexico's obsession with the female body. Her portraits, purposefully small, addressed a wide range of topics not being addressed by the mainstream art world at the time. These included motherhood, domestic violence, and male egoism. Her paintings never had subjects wearing lavish jewelry or fancy clothes like those found in muralist paintings. Instead, she would sparsely