The thing that struck me most was the way he stuck to the motif [in the 'Flag' and 'Target' paintings by Jasper Johns].... the idea of stripes – the rhythm and the interval – the idea of repetition. I began to think a lot about repetition.

In: The New York school – the painters & sculptors of the fifties', Irving Sandler, Harper & Row, Publishers, 1978, pp. 215-216