: He uses period-correct pigments, such as blue made from pure azurite and white made from lead oxide .
: Donovan intentionally leaves the painting unsigned , arguing that since many authentic Rembrandts are unsigned, it is more convincing to let experts "discover" its identity themselves. Plot Resolution Incognito(1997)
: He uses a photograph of his own father as the model for the portrait. : He uses period-correct pigments, such as blue