Forensics in Art

Forensics in art

 

The painting “The Sacrifice to Vesta” is thought to have been painted by Francisco Goya in about 1771, yet despite attribution by many experts there has been no proof found in the form of a signature. It is thought that the signature has become obscured by discoloured varnish. As it was probably done in charcoal, the signature is esentially made of similar material to the canvas and paint, so does not show up on X-ray images. However, terahertz radiation can reflect from different layers of material as well as from different chemicals. By scanning this image one square millimetre at a time, researchers detected a signal that appears to be the “G” and “ya” of Goya to the right of the bottom of the frame. Here the visible light image is at left, the terahertz image at right, and a merged image in the middle.

Image © University of Barcelona, Microwave and THz Laboratory of Prof. J Tejada 

 

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