He [Renoir] is a subtle and brilliant draughtsman.... all these preliminary drawings [in Renoir's studio] would astonish the public who obviously imagine the 'Impressionists' work at tremendous speed. I don't believe one can go further [in making sketches as studies] than this in the study of form in a drawing. I am charmed by his 'Nude Bathers' quite as much as those by Ingres. He [Renoir] tells me that he thinks the nude is absolutely indispensable as an art form.