© 2009 by Anthony Foo.
This is one of the many great advantages of paperclay. A variety of organic material can be kneaded into or coated with paperclay to create interesting textures. Materials such as grains (rice, beans, etc), sawdust, straw, rice husks, pasta, cotton twine, steel mesh, even high fired fragments embedded into paperclay will fire successfully.
I will use the example of incorporating cooked rice (left over 1-2 day old is best - the kind you use to make fried rice) into paperclay as an example here. I use Brown rice here as this is what I eat at home. White rice works just as well.
This has become my trademark texture for my hand pinched bowls/cups. I've added as much as 50% cooked rice to 50% paperclay. A higher percentage of paperclay to organic material will be easier to work with. A higher percentage of organic material will be weaker in the bisque stage as there is less clay to hold everything together. I usually use about 1/4 rice to 3/4 clay, by volume. A lot of it is done by eye and feel and becomes more of an art than science. If you want more texture, add more rice and vice versa. Just bear in mind the above comment about post-bisque strength.
This is the reason why cooked rice works with paperclay and not with ordinary clays. The paper fibers in the paperclay act as a wick to transport moisture from the cooked rice to the outside surface and hence allows it to dry. Ordinary clay will encapsulate the moist rice and it takes "forever" for your piece to dry, if it does dry completely at all. I tried one time with cooked rice and Black Mountain sculpture clay and it took over TWO months (in summer temperature and days in the sun) for it to be acceptable for bisque firing. My pinched bowls survived the bisque firing without blowing up. Compare this time scale with a matter of days when using paperclay for your piece to dry and ready for bisque.
You will be asking "Can I use raw rice?" I have not tried it before, but had a student who used raw lentils and it worked fine. The reason I like cooked rice is because during my pinch bowl forming process, I can "mush" the rice to make it conform to the shape I want. Raw rice grains incorporated into the paperclay will not give at all. You can still work with it, but not as easily in my opinion.
Another advantage of using cooked rice is that you can easily carve, sand, grind your work after it has dried completely. Depending on the thickness of your work, it resulting "completely" dried piece has tremendous greenware strength. I've made a piece that is deliberately very thick and after the bisque fire, took a stone chisel to it to chip away the surface to expose the texture below (Gate 3)
You don't have to knead the rice into the paperclay; you can also press the rice onto the surface of the paperclay to create the imprint. In this case, I would recommend using raw rice as cooked rice will just become mush when you press it onto your paperclay. You don't have to worry about the rice grains which are stuck to the surface of your piece. They will fall off or burn out in the bisque fire.
Hope this helps. Please feel free to contact me if you have questions about this article. I'm also interested in learning about other people's experiences with this technique. I hope this article (and future ones) will also encourage other ceramic artists to push the boundaries of paperclay.