PB35 Cerulean Blue, watercolor pigment

PB35, Cobalt Tin Grey, is an inorganic pigment made by calcining cobalt and tin oxides into a crystalline spinel structure. Often modified with alumina or iron oxides, it presents a soft mid-blue to greenish-blue with a subtle grey cast. In watercolor, it is lightly staining with weak tinting strength and may appear to whiten in washes. Known for its stability and granulating texture, it is used for atmospheric skies, misty scenes, and delicate gradients.