Cernit Nature Polymer Clay Basalt 56g Polymer clay for baking. Cernit Nature polymer clay offers a natural look like earth or stone. < li>When mixed with another range of clay it gives very interesting results. You can use your hands, the rolling machine or the roller. Once your piece has been created, preheat the oven to 130º, once hot, insert the project and bake it for 30 minutes at the same temperature. Once cool, you can sand it, polish it... No smell when baking. Does not crack. Brand: Cernit