I came across these articles when I was interested in finding out more about the ‘restoration’ of Rothko wall paintings, now on display at Harvard Museum Gallery, which was carried out entirely by using light.  This restoration was totally non-invasive; the appearance of faded and fugitive pigments (the paintings contained a lot of the light-sensitive pigment, lithol red)  was restored to the eye of the viewer, without touching the art works themselves, by using precision projection of light.

Projected light has been used as a tool in conservation for some time. Digital projectors are now used to restore the appearance of  items such as a Henry VIII tapestry at Hampton Court, while in the case of damaged wall paintings, projecting a reconstruction or drawing over the top is an option which can be considered, to aid interpretation by the viewer.  Famously light is projected on the western facade of Amiens Cathedral to recreate the original polychromy.  This projection is based on research into the original paint scheme undertaken at the time of the conservation work there in the 1990s.

But restoring large-scale paintings, using this method, pixel by pixel, is something new – fascinating, and another breakthrough for non-invasive technologies.

The articles which detail the method for the Rothkos, and how it was done are below:

Harvard Gazette

Conserving and Restoring Art with Light

And here is the Amiens light projection: