A red chalk drawing that is believed to be the only self-portrait created by Leonardo da Vinci has come under new scientific scrutiny as researchers in Europe are mounting an attempt to prevent the work of art from fading.
Researchers from Italy and Poland have tried to ascertain whether the drawing is suffering from the effects of "yellowing," deterioration that results from exposure to light, humidity, pollution and other factors. Their work was carried out at the Central Institute for the Restoration and Preservation of Archival and Library Heritage in Rome.
Da Vinci's self-portrait is believed to have been created in the early 16th century when the Renaissance master was an old man. The work is now stored in the Royal Library in Turin, Italy.
The researchers said they attempted to quantify the concentration of light-absorbing molecules, which are known as chromophores, in the self-portrait. Chromophores are responsible for the degradation of cellulose in ancient documents and paper.
They concluded that the work of art is experiencing a level of yellowing consistent with historic documents stored in "extremely humid conditions or within a closed environment."
Their analysis can be used for future efforts to preserve the Da Vinci work and others as well.
A number of works by Da Vinci have experienced significant deterioration over the centuries, most notably his late 15th century mural "The Last Supper" in Milan.