Slight visual and material differences identified in MS 197 help distinguish the work of Pellegrino di Mariano Rossini from that of his colleague Sano di Pietro.
Pellegrino’s colour palette includes a bright red obtained with vermilion, a muted purple obtained by mixing an organic red with azurite, and a greater range of blues and greens, also achieved with mixtures. Ultramarine blue, used pure in God’s robe, is mixed with azurite in the dark blue Zodiac circle as well as in the blue initial and border decoration. Malachite appears to be mixed with green earth in the green-blue waters which surround the earth at the centre of the Creation scene.
Further differences include the use of a carbon-based black pigment for all the dark outlines, including the square frame surrounding the initial and miniature. In both leaves painted by Sano di Pietro, however, the dark outline of the initials, as well as the outlines of all the decoration in the border, were painted with iron-gall ink. Additionally, microscopic observation of the painted surface of the leaf painted by Pellegrino shows black particles mixed into the paint layers, including pink, orange, yellow and flesh areas. These differences may account for the darker, more sombre and matt effect of Pellegrino’s work when compared with the brilliant luminosity of Sano’s images.
