Plasters in mediaeval mural paintings of Carinthia and their influence on Slovenia

Abstract

The purpose of the present study was analysis of plasters used as supports for mural paintings carried out by what was known as ‘Older Villach's workshop’ and its followers, active in the first half of the fifteenth century in Carinthia (Southern Austria) and Slovenia. The composition of plasters, the number of layers, the application of giornatas and a possible use of lime-wash was of interest, as was the comparison of results obtained, in order to establish a possible technical characterization and connection among the selected wall cycles that show an important stylistic relationship. Small samples were analysed by OM, SEM-EDX and XRD. The results revealed significant differences in the composition of plasters that can roughly divide the murals into two groups. The first group, starting with works by ‘Older Villach's workshop’ and its founder Frederic of Villach, is characterized by plasters made of lime and sand, while the second, starting with Frederic's son, Johannes of Ljubljana, shows a composition of lime and crushed marble or lime-rock. Intonaco was applied everywhere by the system of giornatas, while lime-wash was rarely used. The analyses also made it possible to confirm/reject authorship hypotheses previously suggested by art historians.