Surface micro-profilometry for the assessment of the effects of traditional and innovative cleaning treatments of silver

In this work, the effects on the surface structure of traditional and innovative silver treatments was investigated with multiscale profilometry, using scanning conoscopic holography and atomic-force microscopy. 3D surface metrology was carried out using standard areal amplitude parameters and a multiscale approach. Preliminary results are presented, addressing two aspects: 1) the validation of laser optical micro-pro- filometry for the diagnostics of silver objects, which are challenging due to the highly specular surface; 2) the validation of the dry-cleaning treatment based on rubbers, by adding to the previous study the complimentary analysis of the micro-surface. The results obtained on silver mockups confirm that the proposed dry cleaning methods produce surface variations less or similar to traditional methods. The optical micro-profilometry results are of particular significance since this technique is portable with wide field capability, thus allowing an in-situ use and a real monitoring of actual artwork surfaces.