Said to be the purer form of Cadmium Yellow. See PY35 for much more information. There are several ways to manufacture cadmium yellow which go beyond this entry.
PY37 is also cadmium yellow, and is a harder-to-find version. About ten paint makers offer it in oil. It is often said this is a purer form of Cadmium Yellow, but I had to turn to Artiscreation to find an answer of what this might mean. There I found, "Concentrated Cadmium Sulphide w/ below 15% Barium Sulfide." He also mentions that this variety tends to be a bit redder than PY35. Handprint (Bruce MacEvoy) also echoes that PY37 tends to be redder.
The same health warnings for PY35 apply to PY37. Debate has raged around the 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 not to 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. 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.
These are fairly lean oil paints as far as the oil required.
Cadmium Yellow actually has two pigment codes, PY35 and PY37. PY35 tends to be for cooler yellows though has quite a range, while PY37 makes warmer yellows. PY35:1 and PY37:1 are cheaper ways of making cadmium yellow which have less strength.
