Observation of samples surface with magnification between x50 and x1000. Reflected light, bright field or polarized light.
Optical observation of the surface or section of painting, metals, stones, fibres, etc. Allows to describe stratigraphy, pigment particles, metallic and organic structures, porosities, alterations, etc.
Under an electron beam, the atoms constituting the matter transmit secondary and backscattered electrons that are collected by specific detectors and allow the observation of the topographic and the chemical contrast of the samples surface, with a magnification up to x50000.
Microscopic observation with very high magnification. Allows study of alteration facies, of microscopic particles morphology, etc. Gives information about samples composition heterogeneity.
This technique consists to passing an X-Ray beam through an object and to collect transmitted X-rays with a CCD sensor. This sensor allows to obtain a black and white image with contrasts varying with the density and thickness of the materials.
Paintings: detection of repainting, of repentance and posterior interventions. Verification of conservation state of the support (alteration, cracks, tears, etc. Sculptures (stone, metal, wood, etc.): verification of the material homogeneity. Detection of ulterior additions, repairs, etc.
Varnish and most pigments are transparent under near infrared lights. The graphite, on the other hand, is not, as a few pigments. It is then possible to take photographs of painting with an infrared camera that only reveals some elements reflective in this spectral range and giving information non-visible to the naked eye.
Exploring of the underlying layers: preparatory drawings, inscriptions, etc.