Figure 5

(a) Microscopic image of a multi-layered plaster from building 17, the consecutive marl layers are observable, separated by red pigment or by soot (Photograph by G. Busacca); (b) Example of a monochromatic red wall painting from building 59 (Photograph by J. Quinlan); (c) Example of a wall painting with geometric motif from building 80 (Photograph by J. Quinlan). Figure generated with Adobe illustrator 23.0.6 (http://www.adobe.com/fr/products/illustrator.html).