XRF Imaging (MA-XRF) as a Valuable Method in the Analysis of Nonhomogeneous Structures of Grisaille Paint Layers

Edyta Bernady,Małgorzata Walczak,Maria Goryl

doi:10.3390/heritage4040179

Abstract

Stained glass paint layers made with vitreous paints can be a challenging subject for analyses. Their heterogenic structure requires proper experimental methodology in order to obtain valuable data. The main goal of this paper is to present the advantages of macro-XRF scanning (MA-XRF) in the non-destructive investigation of historical grisaille paint layers on the basis of research conducted on seven stained glass panels from the Dominican Monastery in Kraków, the Diocesan Museum in Kielce and the National Museum in Poznań (Poland). The obtained results showed the capabilities of MA-XRF scanning in technology recognition, the legibility of damaged fragments of painted depictions, as well as with distinguishing the elemental composition between vitreous paints in different colours. Additionally, SEM-EDS measurements are presented so as to acquire quantitative results and additional information concerning light elements.

Highlights

Introduction of Nonhomogeneous Structures ofStained glass studies are mainly focused on analysing technology and the deterioration of glass
As the research questions for the medieval and 20th century grisailles were different, the results presented below are divided into two groups: glass panes from 1385 to 1500 and glass panes after 1902
In the black grisaille paint that was visible on the glass pane from the oldest stained glass window that was analysed, mainly lead and copper were detected

Summary

Introduction

Stained glass studies are mainly focused on analysing technology and the deterioration of glass. The lack of interest in the study of grisaille paint layers results from the difficulties of analysing nonhomogeneous structures. The second reason may be that it is often not possible to collect a representative paint layer sample from a valuable stained glass window. Interesting reviews on the characterisation of historical grisailles [1] and regarding the technology of the vitreous paints [2] were recently published. The characterisation of components of grisaille paints is crucial to determine the possible origin and age of painted stained glass. Grisaille paints were made by mixing finely ground metallic oxide (as pigment) with lead glass (called flux). The manual mixing of the ingredients and painting techniques were responsible for the final proportion of ingredients and the nonhomogeneous distribution of paint particles on painted glass surfaces

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