Morrisseau was a self-taught artist. He developed his own techniques and artistic vocabulary which captured ancient legends and images that came to him in visions or dreams. He was originally criticized by the native community because his images disclosed traditional spiritual knowledge. Initially he painted on any material that he could find, especially birchbark, and also moose hide. Dewdney encouraged him to use earth-tone colors and traditional material, which he thought were appropriate to Morrisseau's native style.