Multi-technique characterization of dyes in ancient Kaitag textiles from Caucasus

Kaitag textiles, named after the Kaitag district of Southwest Daghestan, Russia, where it is being manufactured, are a unique embroidered textile art form. They were used by families on special occasions such as the birth, marriage or death of one of their members and were thus passed down from generation to generation as family heirlooms. Today, only a few hundred of these precious antique specimens can still be found, and surviving examples are mostly from the seventeenth and eighteenth centuries. In this article, an extensive work for the scientific analysis of Kaitag textiles is presented as the logical continuance and updating of the investigations performed by thin layer chromatography almost two decades ago. A multi-technique approach involving the combined use of micro-invasive and nondestructive techniques suitable for in situ analyses was used, aiming to identify the colourants of Kaitag textiles and the inks employed for the underlying drawing. Analyses were performed by high-performance liquid chromatography, surface-enhanced Raman spectroscopy, scanning electron microscopy combined with energy dispersive X-ray analysis, as well as visible reflectance spectroscopy and X-ray fluorescence. In addition, infrared reflectography and ultraviolet fluorescence were employed to visualise underlying drawings and possible restorations. Corrosion phenomena observed in brown-and black-dyed areas were also investigated.