Evaluating possible prehistoric cave art in the central Mediterranean: Analyses of pigment traces and identification of taphonomic processes at Għar Ħasan, Malta

•Most of the analysed pigment traces were applied within the last century.•One key panel is likely older and may have been painted in antiquity.•Pigment in a poor state of preservation introduces many variables of contamination.•Low-tech methodologies (microscopy and image enhancement) were extremely successful.