Georgia O'Keeffe used oil on canvas for Cow's Skull: Red, White, and Blue. Painted in 1931, the work presents a bleached cow skull against a vivid background of red, white, and blue, linking a Southwestern object with colors associated with the United States.
O'Keeffe frequently collected bones and other natural forms in New Mexico. She enlarged or isolated them so that their shape, texture, and emptiness became the focus of the composition. The skull therefore functions as both a carefully observed object and a highly designed modernist image.
The medium can be confused with O'Keeffe's watercolors and charcoal abstractions, especially because she worked in several media throughout her career. This particular painting is an oil on canvas, and its strong opaque colors are characteristic of that technique.