Since the late 13th century and throughout the 14th century, the fresco painting technique develops in a more complex and accurate execution and “mimesis”, similar but not coincident with the one pertaining to the ancient Roman painting, as it occurs in the mural painting cycle at the basilica di San Francesco ad Assisi and the frescoes by Pietro Cavallini at the basilica di Santa Cecilia in Trastevere in Rome.
The organization of the paint layering evolves in respect to the so-called Pre-Romanic and Romanic periods: the layers of mortar include the “arriccio” and the “intonaco”, the use of the preparatory drawing “a sinopia” on the arriccio is adopted and the procedure involving the application of the intonaco per “giornate” allows more limited and controlled areas to be decorated at every turn, as already known by the Romans. Subsequently, the system of color overlayering is also abandoned in favor of the system of color juxtaposition, which gives the painting that peculiar and luminous compactness.
Moreover, in the 14th century, a more conspicuous change involves the use of the “spolvero” gradually replacing the preparatory drawing “a sinopia”, yet only for ornamental elements.
MR