Friday, August 20, 2010
Cadmium red and other red pigments
As I have said before, I learned to paint with real vermilion. That is pure mercuric sulphide, and deadly. I don't think it is available today, but when I choose a warm red I look for one that has the same qualities as vermilion. Cadmium red is only close.
Cadmium red light is an opaque, permanent warm red and cadmium red medium and deep are progressively cooler. Cadmium red deep is a cherry color, cadmium red light is a fire color. However I find that cadmium red is not as good a mixer as the vermilion was, it tends to give somewhat muddy mixes with many colors excepting cadmium yellow. I use cadmium red mostly to influence, or "step on" other mixtures. I have referred to doing this in the blog before, as smuggling red. A color that is good for stepping on other colors doesn't need pigmenting strength, but mixability so that it adds it's influence to the mix without blowing it out.
Cadmium reds are a standard on the artists palette, but they are expensive and they are a toxic heavy metal. I seldom use it these days as there are other reds out there which seem to be good substitutes. Most of the makers have a red with their own nameplate on it, such as Rembrandt red, or Sennelier red and I like those very well and they are often close to my vermilion standard.
Napthol red is a deep, intense, permanent, semi-transparent red that is somewhat roseate in hue. It has been in use for almost a hundred years and is a common replacement for cadmium red. It is less expensive than cadmium red and I think it gives cleaner mixtures. Nearly every maker sells a napthol red. Again, often these are labeled with the makers name. Sometimes the tube will say permanent red.
Azo is a weaker red and seems to have no advantages over the quinacridones and seem mostly to show up in the less expensive hues or student colors.
P.S. Several people have let me know where real vermilion can be obtained. Even though you can get it, you should not be using vermilion. It is highly toxic and can be absorbed through the skin. I own several old tubes that I keep just to remember what olor it really is. I am have often used lead white and I am willing to deal with that level of toxicity, but vermilion is too poisonous for anyone to use, in my opinion.