Cobalt Blue is a cool blue that can function as the only blue on an artist's palette if needs be. It is more opaque than Ultramarine which gives it excellent covering power. It is perfect for making a wide range of blue, green and violet colours.; Sennelier gathers only the finest organic and inorganic pigments from around the world. These pure pigments are ground very slowly with extreme care to an extra-fine consistency. They are then combined at maximum concentration with an archival safflower oil to yield the highest possible tinting strength and a rich satin finish. This paint has a unique buttery texture.