Marbling is the art of floating paints on top of a thick solution, called size, manipulating the paints into patterns, then transferring the pattern to an object by gently placing the object on top of the paints. I most commonly use either paper or fabric, but have also marbled some luscious pieces of leather, and also small pieces of brass.
I start the process by applying alum to my fabric and/or paper. This is essential to ensure that the paints will adhere to the surface. Next, I fill a shallow tray with size, which is a thick mixture of carrageenan and water. When I drop the paints onto the size, they will float on top. After I have added all the colors that I want, I manipulate the pattern with tools, such as rakes, combs or a simple bamboo skewer. When the pattern is finished, I gently lay the fabric or paper on top, then lift it off. The paint leaves the surface of the size and is now transferred to the fabric or paper. I rinse it immediately, then hang to dry.
Paper marbling has a long history, and many cultures in the Mideast and Far East have used this technique, with slight variations. Even when the same pattern is created, exact duplication is impossible.