teachingstudios:

John Singer Sargent, Caroline de Bassano, Marquise d’Espeuilles (detail), oil on canvas, 1884

Sargent worked mostly with half tones before finishing a painting with the dark tones and highlights.

He’s quoted as saying,″If you begin with the middle-tone and work up from it towards the darks so that you deal last with your highest lights and darkest darks, you avoid false accents.″