Marbling is an ancient art form that has evolved across diverse cultures. It has traditionally been used to decorate paper for bookbinding. Remarkably, its practice has remained relatively unchanged for centuries: Marblers float paints on a viscosified water surface and use various tools (including styli, rakes and combs) to craft intricate or freestyle patterns and print onto a mordanted paper. In the modern era, many marblers use water mixed with carrageenan powder for the bath and diluted fluid acrylics for paint to marble on paper, fabric, wood, glass, rock, and any surface imaginable.
Despite the rich history and aesthetic appeal of marbling, the underlying fluid dynamics has yet to be carefully studied. We celebrate the marbelous hydrodynamics of marbling art by focusing on two characteristic behaviors: First, the paint spreading that sets the initial color arrangement is driven by interfacial forces, and resisted in turn by inertial then viscous forces. Second, low-Reynolds-number mixing allows one to draw on the water surface in a controlled fashion. We showcase examples of traditional marbling patterns and highlight the role of interfacial tension and negligible inertia in marbling art.