Pellegrino Tibaldi, Hamilton
Oil on canvas, approx 6ft x 9ft (copy)
Varnish layer is mastic, it had darkened over time. There were stratified layers of soot particles and other pollutants. There was wide-spread mild craquelure, and hair lined losses/fine cracks. These defects were not obvious except at close scrutiny, due to the surface being obscured by extraneous varnish and dirt. Other areas were over painted e.g. the robe of Mary.
The dirt varnish and over paint was removed. Hair line cracks were filled and retouched with reversible pigments and a binding medium. The entire painting was then coated with layers of reversible varnish mixed with cosmoloid wax for its protection.