The classic 'mixing' yellow maybe as close as we will get to a primary yellow in paint, although pigment technology is moving fast, so who knows! A mid range, warm yellow essential for most painters.
This is a beautiful, rich, pigment dense paint, it is a perfect example of how good these handmade paints are. If you compare this to a generic Cadmium yellow the differences in quality will be very apparent, it has density and colour richness which is hard to surpass.
Pigment - PY35
Opacity - Opaque
Tinting Power - High