"The Marble Index" was produced during a little-studied period of Nico's life. For "The Quietus"s Matthew Lindsay, "the liminal drift of these years only emphasizes the music's amorphous moorings and lack of precedent." Nico approached Danny Fields around the summer of 1968 with the desire to make an album and prove herself artistically. Resentful of her beauty, she radically changed her image – dyeing her hair red and wearing black clothes in an effort to distance herself from what had made her a popular fashion model. John Cale said, "She hated the idea of being blonde and beautiful, and in some ways she hated being a woman, because she figured all her beauty had brought her was grief ... So "The Marble Index" was an opportunity for her to prove she was a serious artist, not just this kind of blonde bombshell." Nico already had the title for the album in mind from "The Prelude", William Wordsworth's magnum opus; in it, he contemplates a statue of Isaac Newton "with his prism and silent face / The marble index of a mind for ever / Voyaging through strange seas of Thought, alone." Asked about the significance of this Wordsworth quote, Nico replied: "I sometimes find a little of my own poetry in other poets, yes. Incidentally, or accidentally."