One of the more interesting things I've learned while getting back into painting is the concept of pigments instead of colors. As you can see from the color swatches I made from two Cerulean Blue paints - the one on the left from M. Graham and the one on the right from Winsor & Newton - that they're not quite the same.
Investigating this more, I find that the pigments that make up the paints are different. The paint from Winsor and Newton uses pigment PB35 which is actual Cerulean Blue. The paint on the left from M.Graham is pigment PB36 which is Cobalt Chromite Blue Green Spinel! The difference is that true Cerulean Blue pigment is very granular and you can see the rough surface it creates on the paper on the right. This granularity was 'solved' by M. Graham by using a different material all together.
Though I have to wonder why they used the Cerulean Blue name, perhaps because it's much more recognizable!
