The Grande Rose of the Reims Cathedral: an eight-century perspective on the colour management of medieval stained glass.

The Grande Rose of Reims Cathedral (France), a UNESCO Cultural Heritage Monument from the 13 century, underwent several restoration works during the 20 century. Its colours result from centuries of colour management from which little information remain. We used non-destructive and portable optical absorption spectroscopy to quantify glass colour and determine the colouring species on a large-scale study of this monumental window.