On the identification of colour photographic processes

For a preliminary screening of colour photographic processes, a visual inspection can be conducted to identify the used printing process and establish the subsequent investigations more consciously.The visual inspection protocols derived from the literature do not offer a completely easy reproducible practice as some require the use of specific instruments with excessive costs. The following study aims to define a more inclusive procedure that exploits portable and inexpensive instrumentation. The methodology proposed is composed of four steps for the study of prints, from the macroscopic to the microscopic scale. The procedure’s applicability was proven by analyzing a set of photographs: the result is a diversification of the collection both in terms of materials and formats. Furthermore, since the prints come from uncontrolled conservation contexts, it was possible to observe the forms of degradation typical of this condition.To present the project, an open-access website called “Color photographic processes –Preliminary identification by visual exam” (https://mips.di.unimi.it/wp/) has been created.