It was in Germany where Aach would be exposed to fine art, studying under German expressionist painter Ludwig Meidner.
After serving during World War II, in Kassel, Germany, he returned to New York in 1946 where he studied under John Ferren and Rufino Tamayo at the Brooklyn Museum Art School.
In 1948 he moved, with his new wife, to Mexico City where he continued his fine art studies at Escuela de Pintura y Escultura.
[1] Upon returning from Mexico, Aach would practice painting in what was described as "relative isolation," between 1954–1963 in Hazleton, Pennsylvania.
[2] At Queens he taught studio art and color theory and became a favorite of students, gaining tribute in the 1968 school yearbook and voted twice as "Teacher of the Year".
[3] Aach's early professional career was heavily inspired by the work of John Ferren and his ideas regarding color theory.
In this series Aach started with covering canvas in thin layers of gesso, inspired by Giotto's fresco-like surfaces.