"Facsimile helps people engage with the content or original appearance of works of art," says Keith. He recalls visiting exhibitions decades ago that used projectors to similar ends. An even earlier example from the National Gallery is Francesco Pesellino's Pistoia Santa Trinità altarpiece, which was taken apart in 1793. When it was reassembled after being gradually acquired by the gallery, a missing section was repainted in order to complete the composition.
