Pannier primarily worked on large, diamond-shaped canvases, painting series concurrently around a single subject. Often inspired by Chicago’s classical architecture, he incorporated dimensional architectural elements into the canvases’ structures. His last major series, Paintings to John Wellborn Root, explored the demolition of these buildings through paired paintings: one intact, the other nearly identical but slashed with a knife to express their destruction and his disillusionment. Supported by an Illinois Arts Council grant, the series was exhibited at Mary Delahoyd Gallery in New York and Klein Gallery in Chicago.