Methodology

For a preliminary screening of color photographic processes, a three-step methodology is used:

Support	Identify the material of the primary support
Image colour and tone	Surface observation with a light source calibrated daylight. The source must be angled to 45°
Format	Express the format in inches or cm
Border	Indicate the absence or presence of a border and its colour
Backprint	Indicate the presence of prints, stamps, dates and inscriptions

Surface sheen	Observation by direct light, placing the light source perpendicular to the plane in which the print is located and moving the photograph by tilting it below the light source. Indicate the type of gloss: matte, semi-matte, glossy, high gloss or differential gloss.
Surface texture	The observation was conducted by placing the light source to form an angle of 45 ° with the plane in which the photograph resides. Indicate the type of surface: smooth surface (reflection of light – glossy surface), rough surface (diffusion of light – matte surface), surface with texture (reflection and diffusion of light – semi-gloss surface).

Image structure	Observation carried out by magnification (10x, 30x, 50x, 100x). The light source forms an angle of 45° with the plane in which the photograph resides. Indicate if the tones are continuous or if there is the presence of dye clouds and white halos.
Layers structure	The light is placed perpendicular to the instrument and parallel to the plane in which the photograph resides. In this way, the paper fibres can be observed. Indicate if: the image is in/on paper fibres (paper fibres visible); the image is above paper fibres, in binder/on coating (paper fibres visible); the image is in binder/on coating (paper fibres obscured).