sinopia

noun

si·​no·​pia sə-ˈnō-pē-ə 

plural sinopias or sinopie sə-ˈnō-pē-ˌā 

1

: a red to reddish-brown earth pigment used by the ancients that depends for its color on its content of red ferric oxide

2

: a preliminary drawing for a fresco done in sinopia

Merriam-Webster

A sinopia is a type of preparatory drawing used by medieval and Renaissance fresco painters as a guide for the artist and a way to show others what they could expect. The historic word does double duty–it’s both the artist’s sketch and the material itself, a red-earth pigment from Turkey.

Sinopia—a global, art historic, and practical word—is a plan envisioned, the underlying structure and organization for the project ahead. 

Andrea del Castagno
Sinopia for Christ in the Sepulcher with Two Angels, 1447
Cenacolo di Sant’Apollonia, Florence