“…Regarding the investigation of the collection of reverse paintings, it is possible to observe that the main cluster comprised of red, blue and green objects is characterized by a similar and simple composition, which is supposed to have the same origin based on the comparison with already assigned reverse glass paintings 22 and, considering the location of the museum, it could be reasonable that they are coming from Sicily where usually glasses show a low Fe content and are red using soda lime. 31 In light of the other clusters, the presence of elemental outliers can drive the assignment. The light blue and yellow clusters could come from Veneto and, in general, from northern regions, because all of them show a low Fe content and the presence of Mn, usually used to make the glass transparent.…”