The habit of breaking up one's colour to make it brilliant dates from further back than Impressionism - Couture advocates it in a little book called 'Causeries d'Atelier' written about 1860 - it is part of the technique of Impressionism but used for quite a different reason.
John Singer SargentI hate to paint portraits! I hope never to paint another portrait in my life. Portraiture may be all right for a man in his youth, but after forty I believe that manual dexterity deserts one, and, besides, the color-sense is less acute. Youth can better stand the exactions of a personal kind that are inseparable from portraiture. I have had enough of it.
John Singer SargentA portrait is a picture in which there is just a tiny little something not quite right about the mouth.
John Singer SargentCultivate an ever continuous power of observation. Wherever you are, be always ready to make slight notes of postures, groups and incidents. Store up in the mind... a continuous stream of observations from which to make selections later. Above all things get abroad, see the sunlight and everything that is to be seen.
John Singer Sargent