We think Sennelier Oil Pastels are the best oil pastels you can buy. They differ from oil bars in that they do not ever completely dry and remain heat sensitive because they are made using a unique blend of natural waxes. It is therefore recommended that oil pastel work is sealed with oil pastel fixative. Try blending them on a surface using a stiff brush and some turpentine. The oil pastel range consists of 110 classic colours and 10 iridescent colours.