I used cardboard from discarded package, shredded it, covered it with hot water and a squirt of washing liquid and let it soak for a few days. Then I mixed the whole thing in a mixer, drained excess water, squeezed, added some plaster and vinyl glue to make the mass clay-like. I used a bowl as a mould, which I had covered with plastic foil, and covered it with the mass, smoothing the surface and giving it a nice shape. I let it dry a bit and, before it hardened because of the plaster in it, I stuck rice grains on it adding some more vinyl glue. I let the whole thing dry and at the end I brushed in a thick layer of enamel powder mixed with water. I added finishing varnish to keep rice grains well in place.