As oil paint ages and becomes more translucent over centuries, earlier versions of a composition — changed poses, removed figures, rearranged objects — can ghost through the final surface. This visual repentance, called pentimento, gives conservators and art historians extraordinary access to an artist's process. X-ray and infrared imaging reveal far more, showing entire hidden compositions beneath the visible surface. The term comes from the Italian for 'repentance' — the painter changing his mind, painting over, trying again. Beneath Raphael's School of Athens, a different head position is visible where he repainted. Beneath Vermeer's Girl with a Pearl Earring, early examination suggests the background was once different. Lillian Hellman used the term as the title of her memoir, making it a metaphor for memory's layered, revised, partially confessed nature.