The stained glass panels of the collection under study will be characterized with respect to the composition of glass and the decoration elements as enamels, grisailles, yellow silver staining and others, fundamental for the identification of production centres and techniques.

Due to the historical importance and cultural significance of these stained glass panels non-destructive analysis will be performed in order to obtain abundant information, meaningful from both the historical and technological points of view, while preserving the valuable objects. Most of the elemental quantitative analysis will be conducted by X-ray microanalysis (EDXRF and PIXE) and UV-Vis absorption spectrometry. From the elemental composition of the glass we can extract information about the provenance and production date, because raw materials used for the production of both glass and painting materials changed in time and according to the production site. In addition to these techniques the surfaces of stained glass panels be analysed with micro Fourier Transform Infrared spectrometry (FTIR) and micro Raman spectrometry in order to characterize painting materials and corrosion products that may be found on the glass surfaces. These results will be fundamental for the development of task 4.

In this task the statistical analysis of the data obtained in the chemical characterization of the glasses will be carried out. Multivariate analysis such as cluster analysis (CA) and principal component analysis (PCA) will be used. The amount of compositional data generated will be substantial, requiring multivariate statistical methods to quantify the similarities and differences between specimens and groups of specimens. CA and PCA are tools used to identifying patterns in data, and expressing the data to highlight their similarities and differences. They are useful methods for characterising element compositional variations in suites of glasses.

An extensive bibliographic research will be developed concerning the historical and analytical characterization studies made in the past years related with European stained glass from 14th to 18th centuries. The original data resulting by this project will be compared with the analytical results on glass compositions of the same chronology produced in European production centres. To characterize compositions of glasses, research groups all over the world use essentially the same analytical techniques, allowing the results to be directly comparable.