Imaging and Technical Analysis
An important component of treating works of art is understanding as much as possible the materials and techniques used by the artist. Specialized imaging techniques can reveal alterations made during past restorations and their affect on the appearance of the painting enabling the conservator to undertake the most prudent and appropriate conservation treatment. Knowledge gained through examination and analysis may also help answer questions of attribution and dating.
Ultraviolet (UV) Induced Visible Fluorescence
Ultraviolet light, which is invisible to the human eye, excites electrons in the molecules of certain materials on a painting's surface causing them to emit visible light. Materials that are not excited will absorb ultraviolet radiation and appear dark. The characteristic fluorescence or absorption of the various materials enables the conservator to discern varnish layers present on the surface and the degree to which they have degraded. By contrast, restorations typically absorb ultraviolet illumination and appear dark against the varnish and underlying paint layers. With this examination technique non original additions, alterations and damages are revealed.
Normal light (left) and ultraviolet induced fluorescence image (right)