The following question is frequently asked: “How is it possible to treat paper with water, i.e. use the procedure of water immersion, despite its fragility?” Paper is a material obtained by a wet, aqueous process, in which the paper pulp is separated from the aqueous suspension and dried. Therefore, a treatment with aqueous solutions is needed in order to remove stains and neutralize acidic degradation products, provided, of course, that the ink is resistant to water.