Most laboratories that aim at the scientific examination of artworks propose a set of observations of the paintings.
Two types of studies are unevenly implemented:

1. The Scientific examination

Non-destructive, it usually offers four separate examinations: photography under tangential light; Infrared Reflectography; Wood fluorescence (examination under Ultraviolet fluorescence) and X-Ray.

The lacuna and preparatory drawings are barely legible in low density layers by X-rays

The lacuna are barely legible in white layers under IR.

The radiography can only observe the density of materials, low density pigments cannot be observed, and if the preparation contains lead radio gives some poor results.

2. Scientific analysis

It is here to analyse the paint layer to know the chemical strcture.

There are many eniques.

The most common are:

SEM analysis (Scanning Electron Microscope), to know the chemical composition of the pigments or fillers used.

X-ray fluorescence spectrometry (XRF)

The gas chromatography to know the binders used.

The experimental protocols used are often unsuitable for artworks. No objective link for synthesizing the informatio gathered.

The results generally fail to accurately determine the genesis of the work.

These inaccuracies had deeply affected the image of the scientific examination of works of art.

The result obtained is in the form of a record made of some pictures and sometimes a comment.

The competence of personnel who carry out these studies is generally not that of the art historian nor the restorer.

During these examinations the number of shots is limited Coming from different media (digital photography, particle accelerators, radiology ...)

They cannot be combined. The colour treatments are carried out by arbitrarily assigning a color to a grey level images in Black and White.

The images are only slightly processed after scanning.