There was excitement when Bismuth Yellow was introduced a few years ago that it might be a safer alternative to the Cadmiums which were under suspicion as carcinogenic substances and might therefore be banned eventually. Bismuth Yellow is not just safer but also has the advantage that it is opaque like the cadmiums. It is a beautiful cool light yellow very similar to Cadmium Yellow Light and has the same uses for the artist.
It does have an advantage over its Cadmium cousin in lightfastness. Cadmium Yellow is naturally a very warm yellow and to get the cool primrose color it is co-precipitated with zinc sulfide. The zinc component reduces lightfastness compared to other cadmium pigments. Bismuth Yellow avoids this problem by having lightfastness that equals or exceeds that of the pure Cadmium Yellow and is superior to the Cadmium Yellow Light.
Chemical Description: Bismuth vanadate
Pigment Number: PY184
Lightfastness Rating: ASTM I
Pigment Opacity: Opaque
Paint Opacity: Opaque