Revealing the unknown: how multi-technical approach can be crucial in identification of dyes and protein in archeological remains

The analysis of archaeological textiles is a challenging undertaking, because of the high information content that characterizes these precious remains. Their realization, from the point of view of the dyes and yarns used, can have multiple meanings, for example the wealth of the commissioner and reflect the cultural taste of the society. The raw materials also can reveal the commercial routes, this may not be evident from literary sources and become clear from the archaeometric study of these artifacts. However, the alteration processes to which these materials have been subjected to, such as thermal aging and carbonization, mineralization, etc., represent an extremely critical point for their study and conservation, because these chemical processes are not entirely known and could bring to a complete modification. For these reasons, the identification of their composition requires high sensitivity techniques, characterized also by great versatility. Recently, multi-technical approaches, based on spectroscopic and spectrometric techniques, have been revealed as powerful strategies in providing information about chemical composition of archaeological relics; they have been employed for characterization of dyes and moreover proteomics and genomics. In this chapter a review of the state of the art of FTIR, Raman and mass spectrometry analyses applied to archaeological fabrics will be provided, also reporting several case studies to highlight the potential of these multi-technical analyses