Composition of 12–18th century window glass in Belgium: Non-figurative windows in secular buildings and stained-glass windows in religious buildings

A set of ca. 500 window glass fragments originating from different historical sites in Belgium and covering the period 12th–18th century was analyzed by means of electron probe microanalysis. Most samples are archaeological finds deriving from non-figurative windows in secular buildings. However, the analyzed set also contains glass sampled from still existing non-figurative windows in secular buildings and stained-glass windows in religious buildings. A sudden compositional change at the end of the 14th century can be noticed among the series of glass compositions that were obtained. These changes could be related to the use of different glassmaker recipes and to the introduction of new raw materials for glass making.