Micro-analytical Study of the Mordant Gilding Technique in Three Post-byzantine Churches in Thessalia, Greece

The wall paintings from the main churches of three monasteries in Thessalia, Central Greece, all painted in the post-Byzantine period, were investigated using micro-analytical techniques. The main goal was to offer insights into the decorative technique of mordant gilding and to provide evidence on the identity of the painter. INTRODUCTION In the preparation of wall paintings, specific features of the representations were often decorated with gold. For this application, the gold leaf was usually attached onto the areas to be gilded by means of a mordant [1]. This technique, however, has scarcely been investigated and as yet very little is known about its application in Byzantine wall painting. The wall paintings investigated in this study derive from the main churches of three monasteries in Thessalia, Central Greece and were all painted in the post-Byzantine era, more specifically between 1552 and 1560. In particular, the main church of the St. Byssarionas Monastery at Doussiko was painted in 1557 by Tzortzis, one of the most important iconographers associated with the Cretan School [2-4]. The main church of the Transfiguration Monastery (Great Meteoro) belongs to the monastic community of Meteora. Its mural decoration was completed in 1552, with the exception of the older-constructed sanctuary, and it is considered to be a masterpiece of the Cretan School [5-7]. Lastly, the Roussanos Monastery is also part of Meteora. Its main church was decorated in 1560 with wall paintings that represent the mature artistic production of the Cretan School [8,9]. Samples were taken from the gilded decoration of several saints depicted in the three churches. The stratigraphy was first viewed in cross-sections using light microscopy (LM). The chemical composition was then determined by electron ionisation direct temperature resolved mass spectrometry (EI-DTMS). This technique led to the detection of the organic compounds and some of their degradation products formed during ageing, as well as of certain inorganic materials. To increase sensitivity towards oxidised molecules, positive ammonia chemical ionisation (NH3/CI) conditions were also applied. The metal constituents were detected by scanning electron microscopy – energy dispersive X-Ray spectroscopy (SEM-EDX). The main objectives of this study are the characterisation of the mordants, in terms of function, properties, and chemical composition, as well as the study of the deterioration changes occurred due to ageing. Furthermore, the layer build-up and the chemical composition of the mordants were compared to check on and possibly provide evidence on the identity of the painter in the three churches. 1 9th International Conference on NDT of Art, Jerusalem Israel, 25-30 May 2008 For more papers of this publication click: www.ndt.net/search/docs.php3?MainSource=65