The Cartoon is cut up into pieces suitable for the Giornate. The Intonaco is thinly applied in an area that can be completed in one session and it is smoothed with a trowel. When the fresh plaster is firm enough the design from the piece of the Cartoon belonging to that area is transferred to the wall by pouncing or it is incised with a stylus. About two or three hours after the plaster has been laid, water brushed on the wall should be directly absorbed instead of resting on the surface. Then the surface is ready.
Painting can begin and continue for a few hours until the surface no longer absorbs the pigment.
Colour applied after the plaster is set will not adhere. To match each day's work to completed parts and control the painting's ultimate appearance the artist must know what will happen to the colours as they are absorbed, drying and changing day by day as the plaster cures. Paint is applied with 15 to 20 minutes between glazes, to allow crystallization to lock in each layer. Corrections cannot be made. At the end of the day's work unpainted plaster and mistakes are cut away.