Johann Wolfgang von Goethe's (1749–1832) watercolour of a liberty tree in Luxemburg also uses the symbol of the liberty cap.
Johann Wolfgang von Goethe (1749–1832), Freiheitsbaum in Luxemburger Landschaft, 1793, watercolour and pen over pencil; source: Goethe-Museum Düsseldorf / Anton-und-Katharina-Kippenberg-Stiftung.