Precious metal threads from a XVIth century tapestry were visually classified using optical microscopy and scanning electron microscopy (SEM). The nature of the surface metals and the nature of the corrosion products were studied by Energy dispersive X-ray analysis (EDX) and dynamic secondary ion mass spectrometry (SIMS).The cleaning of metal artefacts by UV/Ozone treatment was investigated and the surface properties before and after UVO treatment were determined by SIMS. (C) 2003 Kluwer Academic Publishers.