Most pastels drawings, or more accurately-paintings, are executed on a paper surface.The paper can be toned drawing paper or watercolor paper that has been prepared with tone or actually painted on with watercolor media.For the pastel chalks to adhere to the surface they need a degree of tooth or roughness.Special pastel boards are often prepared from Luan or 1/4" masonite which are sanded and then coated with an acrylic emulsion that contains grit such as pumice or sand.There are even papers that come preprimed with a sanded coating, often toned with color.