The painting representing the Battle of San Martino (24 June 1859), also known as the battle of Solferino and San Martino, probably done on cotton textile by an anonymous author, was carried out with an unusual technique, i.e., using a monochrome sketch painted with a slight tonal range. The preparation layer, the priming, and the actual painting are in animal glue tempera, and the execution technique is poor and not cohesive, as confirmed by the results of the analysis carried out by Stefano Volpin and discussed subsequently. Large areas of the painting were water stained, probably because of its original outdoor location. The cleaning intervention served to remove the incoherent dirt from the surface and to resolve the moisture staining problem. Different tests with different materials and methodologies were carried out.