[Not necessarily about this painting just notes on painting in general from Sargent.] • Painting is an interpretation of tone. • Keep the planes free and simple, drawing a full brush down the whole contour of a cheek. • Always paint one thing into another and not side by side until they touch. • The thicker your paint — the more your color flows. • Simplify, omit all but the most essential elements — values, especially the values. You must clarify the values. • The secret of painting is in the half tone of each plane, in economizing the accents and in the handling of the lights. • You begin with the middle tones and work up from it .... so that you deal last with your lightest lights and darkest darks, you avoid false accents • Paint in all the half tones and the generalized passages quite thick. • It is impossible for a painter to try to repaint a head where the understructure was wrong. — John Singer Sargent [http://www.powersofobservation.com/2012/01/sargent-on-painting.html]