For a preliminary screening of colour photographic processes, a visual inspection of the prints can be conducted, from the macroscopic to the microscopic scale. This examination allows us to understand the printing process used, in this way we can be able to establish the subsequent investigations more consciously.

The protocols for the preliminary screening, deriving from the literature, offer easily reproducible methodologies only in part as they require the use of fixed instruments, such as microscopes, with relatively high costs that not all archives can support. In this way, the preliminary recognition of the processes is limited and, consequently, it becomes difficult to establish the following investigations.

For this reason, the following study aims to define a more inclusive protocol that exploits a portable, inexpensive and easily available instrumentation.