I came across this fascinating article about an interactive interface created by Met Media Lab intern Betty Quinn, which allows museum visitor to explore the hidden layers of paintings.  The technology used to produce this interface were non-invasive imaging techniques which reveal changes to the original drawings and compositions, and even reuses of canvases.  The full article is here, with the resulting images:

Paintings Uncovered

Meanwhile a new exhibition at the McMasters Musuem of Art in Ontario, entitled ‘The Unvarnished Truth: Exploring the Material History of Paintings’, reveals the findings of technical analysis by an international team of scientists, engineers, conservators and art historians  from nine paintings within the museum’s permanent collection.  Researchers used sophisticated non-invasive techniques including x-ray fluorescence, infrared reflectography, even neutron radiography, to answer questions on painting techniques and materials, attribution, condition and stability.

An article with further details about the exhibition and the research is below:

The Unvarnished Truth: The Material History of Painting