A palette essential. As a pure red it is almost regal it has such presence. A smashing pigment that is opaque, high chroma, and lightfast. Cadmium Red varieties form an arpeggio of colors (that share one pigment code) from red-orange to classic bright red, to rare and moody maroons. Each of these colors is made with the same pigment code, PR108, so painters must try to rely on the paint name (such as Cadmium Red Medium vs. Deep) to try to guess at the color of the paint. One of the reasons we founded Paint List was to help sort this out.
The naming structure for paints can be a bit confusing— in the case of Cadmium Red, it is often labeled as Light, Medium and Deep, and these names follow the spectral progression from orange to dark red. When cadmium red is named Light, it refers to a chromatic red orange, whereas Medium often connotes a high chroma middle red, and the name Deep usually refers to a cooler deeper middle red. Paints labeled Cadmium Maroon or Purple are less frequently found, and these describe dusky dark red-purples.
Each one of these sub-variants gets solidly excellent marks for lightfastness. Bear in mind though that prolonged exposure in direct sunlight (i.e. years of direct exposure) will eventually darken them, though in comparison with other reds their lightfastness is excellent. However it has some sensitivity to moisture, so do keep that in mind.
Opacity can be hard to come by in certain areas of the reds, and the character of Cadmium Red makes it extremely useful as an opaque, bright, lightfast red. All versions are opaque (unless diluted by the paintmaker)-- they cover with finality. The opacity of any given tube may depend on the pigment concentration in that brand.
Also, a quick reminder that lightfastness does not mean the same as weather-fastness. Cadmium reds are sensitive to moisture, so they are not intended for outdoor use.
Debate has raged around the toxicity of cadmiums, and they are listed as pigments with toxicity, so be extremely cautious with them. Lately we have seen a lot of resources suggesting the modern cadmium pigments are engineered to be far less toxic source, another source and another source, compared with regular cadmium. However, we always err on the side of caution with pigments (there is no downside to being super careful) and so we always handle these with respect. Also beware with older cadmiums for many reasons as they may also contain toxic adulterants like lead.
We have read to never breathe them (this means not using them for airbrush). However, we are not experts in health and safety so please consult the relevant authorities on their proper handling and disposal. According to the work of Monona Rossol, cadmium is a carcinogen and causes kidney damage. The Artist's Guide to Health and Safety has more information about the hazards of pigments containing Cadmium as well as Selenium. They should not be sprayed and the dust should be stringently avoided (remember in regard to avoiding sanding). It should go without saying, but absolutely do not ingest any pigment.
PR108:1 is a less expensive way of making cadmium red, but it also has less strength. If a pigment is marked PR108:1, that means it contains more than 15% barium sulfate. We've heard that often PR108:1 has quite a lot more barium in it than just the 15% mark.
In contrast, PR108 regular (also called the CC version) refers to a higher-quality version of cadmium. The CC refers to the concentrated cadmium version.
One interesting thing for oil painters is that cadmium reds and the related cadmium-barium reds as having rather lean to medium oil requirements, which relate to their use in lower levels of an oil painting. If additional driers have not been added, they do tend to dry slowly.
Overall, Cadmium Red is a superb pigment for use by professional painters.
