III International Conference

PP-I-9formed on their place. The PI color is determined with the packing density of such particleson the layer parts with the different optical density (D).In the other variant the stages of oxidation and reduction follow one after another. Theoxidizer is I 2 in the KI solution. The reducers are methol, phenidone and hydroquinone invarious combinations. The oxidation product AgI is reduced under the action of the lightduring its contact with the reducing solution. Probably, the silver particles formed as a resultof photolysis, catalyze the Ag + reduction from the AgI lattice with the colloidal silverparticles formation. Their size is not equal on the parts of image, varied by the D value.The method (3) is based on the oxidizing-reducing reactions taking place in theconditions, when the filamentary silver of the common black-and-white image can betransformed not only into colloidal silver particles, but into colored ferrous-ferric complexesas well. The rate of these reactions and the nature of their products are also determined by thesilver concentration on the image part with different D initial.24