Understanding is an elusive and little understood concept yet it is frequently cited as an educational aim. The aim of this paper is to illuminate the nature of understanding in the art education context. This paper explores critically the conceptual background of understanding, drawing on the work of Wittgenstein, to reveal its varied and indeterminate nature and the importance of public criteria in the sharing of understanding. Focusing on art, the paper shows how understanding involves an experiential and imaginative synthesis of a work's concepts and features, inexpressible aspects and the viewer's subjective contribution. The importance of giving an artwork its due as an artist's creative achievement is supported. Notes for teaching response to art are offered in keeping with understanding's open texture.