Stick to it! Mechanical performance tests to explore the resilience of prehistoric glues in hafting

peer reviewedKnown preserved glue remains are relatively rare, but they witness a broad range in glue types that may have existed in the past, varying in terms of the main component and additives. However, archaeological experimentation rarely mirrors that variety, leading to a certain lack of information on the behaviour and interest of several traditional glues, notably animal-based glues. Through mechanical bench testing (shear–compression), this paper aims to document the resilience of 11 different glues and mixtures in combination with three different organic substrates and flint, in order to reproduce a realistic hafting system. Results highlight that glue performance depends on the hafting materials used, thereby demonstrating that the choice of an appropriate glue depends on the hafting arrangement envisaged. The results also indicate that no glue outperforms all others or witnesses universal applicability. We therefore argue that glue use and performance should be evaluated from the perspective of the complete tool within a particular use context and environment. Only such an integrated perspective permits to reflect on the role of glue in past tool technologies, including its manufacture, composition and use, and on the significance of glue with regard to human behaviour and its evolution