AZ: The pictorial film has its own morphology, made up of roughness and hollows. The canonical cleaning method, by rubbing a pad soaked in solvent or solvent mixtures, would have insisted on the cusps without being able to reach the deep micro-interstices. The Agar gel, on the other hand, acts by incorporation, also insinuating itself in depth to capture the incoherent deposits. It does not require rinsing, unlike many canonical gels, and has no adhesive power, so it can be eliminated without exerting any traction on the paint film. We have therefore created masks based on Agar Agar, perfectly corresponding to the portions of the painting on which we were going to intervene from time to time. At the moment of overlapping the mask, sometimes added with previously tested solutions, is completely transparent, then the Agar acts and depending on the amount of incoherent materials absorbed, its color turns towards a more or less dark brown. At the end of the action, the bezel is simply lifted and removed. After cleaning, details of the composition re-emerged that were almost illegible as well as the lighting of some colors, such as whites and reds. But above all, the intervention has, as far as possible, restored to the «Deposition» the characteristic opacity of tempera, a precise choice by Lotto.
Antonio Zaccaria tells of the restoration that the Creberg Foundation donated to the city of Bergamo