Painting before the plaster dries

In the wall-painting technique known as true fresco, artists apply pigments to fresh lime plaster. As the surface dries and hardens, the color becomes integrated with it. This method can produce durable paintings, but it places a limit on the painter’s working time.

A wall cannot simply be coated with wet plaster and painted over several weeks. [A] Once a section has dried, it no longer accepts color in that way. [B] Workers therefore prepare only as much fresh surface as the artist expects to finish that day. [C] The next section is added when work resumes. [D]

Planning these sections is part of the composition. A painter may place a join along the outline of a figure, where the boundary attracts less attention than it would across an open sky. A complicated face can require a smaller section than a broad area of clothing, because equal surface areas do not necessarily demand equal working time.

The resulting painting may appear continuous, although its surface records a sequence of separate efforts. Close examination of the plaster joins can reveal that sequence. These boundaries offer information about how the work was organized, including the size and placement of portions prepared for individual painting sessions.