These oil crayons from the Danish company Filia have been a classic for decades. The lightfast colors are transparent and mix very well. They offer many interesting painting and drawing techniques. With a sponge and turpentine, it is possible to "watercolor paint" with these hard, oil crayons.
These classic crayons are square and have a tip for outlining or two-dimensional drawing and shading. They have no wrapper so you can use the entire crayon to apply color.