Context
Analysis of smalt discoloration in paintings by X-ray absorption spectroscopy

The creation (design) of a work of art begins with the choice of basic materials (support, construction), then the materials used to create the play of color and light on the surface. The choice of the latter may be based on the symbolic power of the raw materials, their stability, ease of supply, low cost, or their actual physical properties. These include color. Natural minerals were initially used as the basis for the colorful creation of paintings and painted objects, before being rapidly supplemented by manufactured materials: colorants extracted from plants, synthetic pigments such as cerussite or Egyptian blue, etc.

The aim of this human intervention was to replace nature in order to obtain a colored material with the qualities required for painting: compatibility with binders and other pigments, inertness, tinting strength, etc. The problem of blue proved...