For his Guggenheim Fellowship in 1972, Ferro embarked on a series of mixed-media collages, which included not only his beloved woodcut process, but also expanded to incorporate watercolor, gouache, cut and torn paper, tape, canvas, oil paint, and other items, including in at least one work, a corn husk. They exist as some of his most free form and experimental works. In addition to these collage experiments, other endeavors beyond his primary mediums of woodcut, watercolor, and illustration included a number of drawings, a public art work for an open-air market in Jeddah, Saudi Arabia, and several sculptures for commercial clients. The true breadth of these works continue to expand as his family posthumously discovers more.