Consolidation tests in archaeological wall painting: comparing treatments depending on the painting technique

Consolidation is a treatment of great importance for archaeological wall paintings due to their state of preservation, in which the lack of cohesion of the mortar and the pulverulence of the pictorial layer are common. The objective of this work has been to evaluate consolidation tests that have been carried out on decontextualized fragments belonging to five different wall paintings (from different periods and with differences in their state of conservation and in their painting techniques). For this, two of the most used treatments in consolidation of archaeological coatings, such as an acrylic resin and ethyl silicate, have been compared with two treatments that use nanoparticles, such as nanolimes and nano ethyl silicate, together with a bioconsolidation treatment used until present mainly for the consolidation of stone material: bacterial carbonatogenesis.