Addressing backing techniques through high-magnification microscopy and quantitative analyses

The application of backing techniques is a central element in the manufacturing process of Upper Palaeolithic and Mesolithic lithic projectile implements (e.g., backed points, backed bladelets, backed and truncated bladelets, geometrics, etc.). In recent years, different studies based on a low magnification analysis have been developed to provide a more accurate and comprehensive understanding of these techniques. Within this general framework, to improve the reliability of backing techniques recognition, this paper explores the application of new methodologies including a high magnification microscopy and a quantitative analysis. The former permitted the observation of several microscopic traces (e.g., polishes and striations) yielding important information concerning the nature of the used retoucher (mineral vs. organic). The latter allowed evaluating the variability of several retouch scars features (angles, depth and size) and their statistical significance to distinguish backing techniques. Both methods were then applied to an archaeological sample of projectile implements from Riparo Tagliente (VR, Italy), providing valuable insights regarding backing techniques used by Late Epigravettian hunter-gatherer groups.