There are different ways of ensuring the authenticity of ancient paintings :
- control of authenticity only through stylistic evaluation
- control of the authenticity of a painting through objective examinations of the aging of the material
- control of the authenticity of the painting carried out with scientific methods based on the use of instruments.
All of the results of checks carried out at the level of style or matter, and scientific analyzes will make it possible to recognize the compatibility of the painting with the presumed data or, on the other hand, its non-authenticity.
Scientific analyzes of paintings carried out according to the methods and with the instruments of a laboratory
Thanks to modern laboratory equipment, a painting can be subjected to various analyzes carried out with
1/infrared reflectography,
2/black light,
3/stereoscopic microscope,
4/IR spectrography,
5/other instrumental techniques.
Microscopic analysis: This analysis makes it possible to study the marks of aging of the paint layer, the properties of cracking (natural or artificial - deep or superficial), pigments (crystallinity, purity, and dimensions), restorations and others.
Black light and monochromatic lights: This analysis makes it possible to assess the importance of restorations, alterations, and new executions. It also makes it possible to recognize several fluorescent substances.
Infrared reflectography. It allows us to study in-depth the painting, to discover the drawings or the underlying grids, changes in the painter's ideas, the depth of the cracks, and to detect restorations or the use of different materials.
IR Spectroscopic Analyzes: They analyze different materials to check their compatibility with the presumed historical period: pigments, binders, glues, and varnishes. These analyzes are carried out with extremely reduced material samples.
IR spectroscopic
dating of wood for dating the frame,
support or frame of a painting.
Evaluation of physical properties of the material
measure of the binder drying and elasticity of the paint layer with the "duroflexomètre."
Conclusion:
A laboratory also digitalizes images obtained by the various techniques,
carries out examinations under reflected and raking light, and performs microchemical analyses.
Certificates are issued with a clear and exhaustive report on the results of the analyses.
Gottfried Mattheas, paintingauthentication.com
