Stability studies of materials applied in the restoration of a baroque oil painting

In the restoration of a baroque altar painting “Coronation of the Virgin Mary” originating in the 18th century, a selection of materials was based on the examination of their stability evaluated by objective physico-chemical methods and by visual inspection. The stability of fillings prepared by traditional recipes, and new ones based on modern, commercially available materials, was assessed. To study the colour stability, techniques of light and thermal induced accelerated ageing were applied. Simultaneous thermal analysis (DTA and TG) was applied in order to study the thermo-oxidative stability of the materials. The commercial contemporary material Litostucco appeared the least suitable of all of investigated samples; however, it is possible to improve its stability by modification with additives, mainly kerotix. The fillings prepared by traditional recipes, with the exception of wax, are suitable for restoration of the oil painting.