Fresco Laser Ablation
Here is a detail of a Renaissance fresco in the Cappella del Manto in Santa Maria della Scala, Siena, Italy, showing three angels. The face of the angel on the right has been cleaned by laser ablation, which vaporizes the surface layer of dirt. This technique has been used in removing tattoos and in cleaning stone and bronze artworks, but frescoes are a far more delicate matter. Having achieved success, Salvatore Siano and Renzo Salimbeni have recently published their findings. Click the title link for details.