A dark blue powder. Do not dissolve in water, soluble in sodium sulfide which was green blue. The concentrated sulfuric acid blue solution was diluted after dark blue precipitation. Right-aminophenol and 2,4-Dinitrochlorobenzene condensation after Polysulfide sulfide oxidation, and then separated in the system. Used mainly cotton, linen, rayon and peacekeeping / cotton blended fabric dyeing. Sometimes also used to stain the leather.