Evaluation of the use of Funori for consolidation of powdering paint layers in wall paintings

Funori is a polysaccharide-based adhesive extracted from seaweeds and is generally used in the conservation of easel paintings for the consolidation of matte paint. It is appreciated since it does not change the optical properties of the consolidated materials and its mechanical properties do not change with ageing. Because of these characteristics, this research focused on the evaluation of Funori as a suitable material for the consolidation of powdering paint layers in wall paintings. Tests were carried out where Funori was applied onto painted plaster replicas, which were then artificially aged and investigated in order to evaluate the material's behaviour according to the specific properties and conditions of wall paintings. The effectiveness of the consolidation was evaluated from the point of view of adhesive power, as well as the interactions of Funori with some physical properties of the consolidated painting, such as colour and water vapour permeability and, therefore, its resistance to accelerated ageing and biological colonization. In addition, the behaviour of Funori applied on plasters contaminated with soluble salts, a frequent condition in wall paintings, was also evaluated.