Research Article 𝜇-XRF Studies on the Colour Brilliance in Ancient Wool Carpets

Many handmade ancient and recent oriental wool carpets show outstanding brilliance and persistence of colour that is not achievedby common industrial dyeing procedures. Anthropologists have suggested the influence of wool fermentation prior to dyeing askey technique to achieve the high dyeing quality. By means of𝜇-XRF elemental mapping of mordant metals we corroborate thisview and show a deep and homogenous penetration of colourants into fermented wool fibres. Furthermore we are able to applythis technique and prove that the fermentation process for ancient specimens cannot be investigated by standard methods dueto the lack of intact cuticle layers. This finding suggests a broad range of further investigations that will contribute to a deeperunderstanding of the development of traditional dyeing techniques. Spectroscopic studies add information on the oxidation statesof the metal ions within the respective mordant-dye-complexes and suggest a partial charge transfer as basis for a significant colourchange when Fe mordants are used