The supports treated with lime or tempera present a low resistance to chalking due to the lack of organic binder in lime.
The phenomenon is characterized by the formation of a thin dust on the painted surface.
Remove dust with a stiff sorghum brush under a strong jet of water and, with the aid of a spatula, remove the old paint layers. Once the surface is completely dry, restore the surface with putty and then apply a water-based fixative. Then proceed to the normal painting with water-based paint.