Raman microspectroscopic analysis of pigments of the Gothic wall painting from the Dominican Monastery in Ptuj (Slovenia)

Abstract

The study deals with the characterization of pigments from the newly discovered wall painting at the Dominican Monastery in Ptuj (Slovenia) in order to acquire detailed information about the technology used, as well as to identify the deterioration products. The uncovered wall painting, depicting a vivid procession of riders, is dated to the late 14th century. Painting techniques and pigments were analysed by optical microscopy and Raman microspectroscopy. The optical microscope revealed that the wall painting was executed in a lime technique characteristic of the Central‐European artistic expression. Several natural and synthetic inorganic pigments, such as azurite, red and yellow ochres, cinnabar, red lead, lead white, lime white, lead–tin yellow type I and carbon black were identified. Surprising identification of the type I of lead–tin yellow used already in the 14th century is of high importance, since, until now, it was considered that it appeared on the market only in the first half of the 15th century. Plattnerite was observed as a result of degradation of lead pigments. The use of expensive azurite and cinnabar could indicate a wealthy client. Copyright © 2014 John Wiley & Sons, Ltd.