On the Identification of Colour Photographic Processes

To determine the best investigations for restoration and storage procedures, a visual inspection can provide a preliminary screen for the colour processes used to print the photographs. The high costs of the instruments required to follow the protocols present in the literature make these methodologies challenging to reproduce, especially for institutions with limited resources. Hence, a cheap and advanced investigation protocol is needed. This work proposes a protocol that, besides having this characteristic, observes the degradation of the material as a factor in identifying printing processes. The procedure proposed is composed of four steps: I. print observation: a preliminary examination of the object; II. surface observation: an examination of the surface; III. magnified observation: examination with microscope; and IV. decay and damage: alteration and degradation analysis. A set of photographs from the 1960s to the 2000s were analysed following the proposed protocol. From these prints, it was possible to observe the typical forms of degradation deriving from inappropriate conservation and determine the different materials and formats, proving the protocol’s effectiveness and easy applicability.In addition, the scientific community may access this protocol through the open-access website Colour photographic processes-Preliminary identification by visual exam.