In 1957 Nolan began using a new medium: polyvinyl acetate. PVA is a synthetic medium which can be used thickly or thinned with water. It was an ideal vehicle for Nolan's painting process. This involves laying down pigment, and then scrubbing, scraping and sponging the paint surface, encouraging the formation of images which are then elaborated. One aspect of the Eliza Fraser story which particularly fascinated Nolan was the bizarre conjunction of a naked white woman and a convict dressed in striped prison uniform. In this painting Mrs Fraser appears as an aboriginal cave drawing while Bracefell emerges from a niche in the rock.