He is remembered for his research on First Nations cultures of the Northwest Coast, notably the Tsimshian, Gitxsan, and Haida, and especially for his interest in their plastic arts, such as totem poles.
Along with Bill Holm and Harry Hawthorn, he was one of a small coterie of academics in the 1950s and '60s who worked to bring Northwest Coast art to international prominence.
He was a founding member of the British Columbia Museums Association, and in the 1950s worked to preserve the last remaining totem poles on Haida Gwaii (formerly the Queen Charlotte Islands).
Gitanyow), arranging for some of the village's totem poles to be removed to the RBCM for preservation, in exchange for replicas and for the publication of the Kitwancool people's histories, territories, and laws.
The subsequent death of Lilo Berliner, a correspondent of Duff who left their letters on the doorstep of poet Phyllis Webb, led to the creation of the memorial poetry sequence "Artifacts" in the collection Wilson's Bowl (1980).