Mike:
I used a verdaccio formula of Flake White, Mars Black and Chromium Oxide Green. I mix them into nine values from dark to light and bracket them with Mars Black and Flake White giving me 11 tonal values from black to white.
For those who might not know, verdaccio is a form of underpainting used since the mid 1300s - primarily by the Italians. The term Verdaccio is Italian for "Greenish-first." Cennini mentions mixing a verdaccio for frescos in his book "Il Libro Dell'Arte" written around 1437ish. Cennini describes mixing powdered pigments of Yellow Ochre, Black, White, and Sinopia or Cinnabresse (Red like Venetian Red to dull the green).
The imposition of warm flesh tones on the cool gray-green really creates a very vibrant and realistic flesh tone.
