The western Arnhem Land style is typified by the art of Oenpelli, in which x-ray paintings, forceful images of spirit ancestors and delicate paintings of the Mimi spirits predominate. These are painted very finely on a plain monochrome background. The earliest paintings collected this century were from the area now known as Oenpelli, and it is these figurative images of hunting animals and stick-like figures which have come to symbolise, for many, the very essence of all Aboriginal Art.

The term x-ray art was originally coined because many of the Oenpelli paintings of figures, animals, birds and fish, reveal the internal organs as well as the external features. Heart, lungs, intestinal canal and spinal column were often clearly shown. Numerous extraordinary beautiful ancient examples of the x-ray style of painting appear on rock faces throughout the area.

Paintings of Mimis in the traditional Mimi art style depict them as thin spirit creatures in various positions which display their extreme agility and flexibility. The oldest cave paintings in Western Arnhem Land are of Mimi figures running and hunting, often wearing head dresses and carrying several weapons and utensils. These type of figures were given the term 'dynamic' by the Rock Art historian, George Chaloupka.

The Mimis are thought to be the original beings who occupied the land before humans and continue to live in rocks, caves, trees and water although they are rarely seen. According to Kunwinjku people mimis taught them everything they needed to know to survive; how to hunt, gather and prepare food, sing, dance and perform ceremonies.