New Elimination Procedure for Silver Mirroring. Silver mirroring is a type of deterioration that appears in most gelatin developing-out paper (DOP) historical photographs and black-and-white films. Its treatment involves so many problems that it has often been ruled out. In this article we present a new and simple elimination procedure, which is efficient and offers stable results in the long term. The study of the causes of the formation of silver mirroring sheds light on aspects that had been little explained so far: the fact that this type of deterioration always appears on the surface of the image leads us to consider a mechanism of transport of electrical charges.