Cadmium Red Light is a synthetic inorganic mineral pigment. Invented in the nineteenth century, this color is a cadmium sulphide which can be obtained with two methods: Starting from cadmium nitrate from which the carbonate is precipitated with Solvay soda and heated with sulfur flowers; From cadmium sulphate with sodium sulphide.
This pigment has a shade that can vary from light orange to purple and has a high covering power. It is incompatible with lead-based paints, but is soluble in sulfuric and nitric acids and can be falsified with solid azos.
Advice for use: It can be used in tempera and oil, while we do not recommend using it for fresco and encaustic.