Pictorial materials database: 1200 combinations of pigments, dyes, binders and varnishes designed as a tool for heritage science and conservation

The conservation of artworks requires a profound knowledge about pictorialmaterials, their chemical and physical properties and their interaction and/or degradation processes. For this reason, pictorialmaterials databases are widely used to study and investigate cultural heritage. At Centre for Conservation and Restoration La Venaria Reale, we prepared a set of about 1200 mock-ups with 173 different pigments and/or dyes, used across all the historical times or as products for conservation, four binders, two varnishesand four different materials for underdrawings. In collaboration with the Laboratorio Analisi Scientifiche of Regione Autonoma Valle d’Aosta, the National Institute of Metrological Research and the Department of Architecture and Design of the Polytechnic of Turin, we created a scientific database that is now available online (http://www.centrorestaurovenaria.it/en/areas/diagnostic/ pictorial-materials- database) designedas a tool for heritage science and conservation. Here, we present a focus on materials for pictorialretouching where the hyperspectral imaging application, conducted with a prototype of new technology, allowed to provide a list of pigments that could be more suitable for conservation treatments and pictorialretouching. Then we present the case study of the industrial painting Notte Barbara (1962) by Pinot Gallizio where the use of the database including modern and contemporary artmaterials showed to be very useful and where the fibre optics reflectance spectroscopy technique was decisive for pigment identification purpose. Later in this research, the mock-ups will be exploited to study degradation processes, e.g., the lightfastness, or the possible formation of interaction products, e.g., metal carboxylates.