Time-efficient methods for reproducing archaeological bronze patinas: New tools for conservation and authentication studies

The reproduction of corrosion patina s observed on copper-based archaeological artefacts is a valuable methodological approach in conservation research, as it allows the systematic study of corrosion processes, material stability, and the efficacy of conservation interventions under controlled conditions. Such reproduction remains challenging due to the complex, multicomponent nature of burial-induced corrosion systems and the extended timescales required to generate representative patinas under laboratory conditions. This study proposes and validates two time-efficient ageing methods for producing representative archaeological bronze mock-ups suitable for analytical characterisation and conservation testing. The first method is an electrochemical protocol, while the second is burial-based and builds upon established knowledge derived from historical counterfeiting processes. The reproduced patina s were analysed in detail both at the surface and stratigraphically, and their characteristics were compared with those of a genuine archaeological copper-based artefact. The electrochemical method yielded compact patina s with a typical cuprite–malachite stratigraphy within only four days, whereas the burial-based approach generated more complex corrosion systems, incorporating soil-derived encrustations and chloride-bearing phases, while still operating on a significantly reduced experimental timescale compared with existing literature. Despite these differences, both methods successfully reproduce key stratigraphic and mineralogical features of archaeological patinas, providing rapid and reproducible mock-ups suitable for conservation research under controlled conditions.