Grimshaw did many posters for the MC5 and worked with the Detroit Artists Workshop, Translove, the Hill House commune in Ann Arbor, Michigan, and later for the Rainbow Peoples Party, successor to the White Panthers.
In 1968, he was indicted on a marijuana charge in Grand Traverse County, Michigan along with Pun Plamondon,[REF] and fled to San Francisco and Boston, where he continued designing posters.