Baker's work at the University of Pennsylvania Museum of Archaeology and Anthropology attracted wider notice, leading many "other ... archaeologists, who had only seen examples of her published work, [to] request... her participation in future efforts." Baker worked in pen and ink, charcoal and watercolor. Her three-dimensional and trompe-l'œil water colors and 'roll out' illustrations of ceramic vessels  were particularly admired as "both scientifically valuable and also exquisite art." In 1931, M. Louise Baker traveled to New Orleans, where she painted Maya material at Tulane University's Middle American Research Institute. Next she traveled to Mérida, Yucatán, in Mexico, and painted and drew Maya pottery in the State Museum and private collections. Next she traveled to Guatemala City, Guatemala, to make ink and watercolor illustrations of pots from the Carnegie Institution of Washington expedition to Uaxactun and from Cobán, held in the private collection of Erwin Paul Dieseldorff. Her paintings and illustrations of Maya pottery were subsequently published by the University of Pennsylvania Museum between 1925 and 1943 in several volumes of "Examples of Maya Pottery in the Museum and Other Collections"; several others appeared in the second volume of E.P. Dieseldorff's "Kunst und Religion der Mayavölker" (1931). Still others have been more recently reproduced. In 1932, Baker traveled to the British Museum in London, England, and then on to Baghdad, Iraq, to paint materials held there from the Joint Expedition of the Penn Museum and British Museum to Mesopotamia. Leonard Woolley served as the excavation director for the Expedition, which uncovered the Royal Tombs of Ur. During her return from Iraq, Baker visited museums and private collections in Germany, Spain, France, Sweden, Denmark, the Netherlands, and England to add to her illustrations of Maya ceramics. Louise Baker left the Penn Museum in 1936 when, owing to her failing eyesight, she had difficulty producing illustrations. She retired from the George School two years later, in 1939, together with E. Constance Allen, who was dean there from 1925 to 1938. Baker and Allen purchased a home together in Wallingford, Pennsylvania. For the next ten years, Baker taught classes on writing and illustration, carpentry, furniture making, metal working, and ceramics. She also gave talks on local and Quaker history and her archaeological adventures, acted in amateur theater productions in Chester County, and led tours to European museums.