Pigment Orange 36 (Pyranthrone Orange) is a semi-opaque organic pigment that yields a dark orange matching Cadmium Orange, but appears brighter than Hostaperm Orange PO 60 when used pure. Although it is slightly less opaque and harder to prepare than traditional Cadmium Orange, Pyranthrone Orange serves as a highly effective, economical, and higher-yielding modern substitute with practically identical durability. Key Properties Excellent lightfastness (Level 8) and temperature stability up to 160°C. Adequate in acid (Level 5), but limited in alkali and lime (Level 3); prolonged exposure to slaked lime causes browning. Unlike most transparent organic pigments, its semi-opaque nature provides highly vibrant, solid coverage without requiring color-dulling fillers. Application Guidelines Works well in all systems but excels in opaque paints. (Hostaperm is recommended instead for watercolors). Requires pre-wetting with alcohol for pure watercolors and tempera. Dispersions require no pre-wetting, and oil only needs simple spatula mixing. Requires a high amount of binder and dries slowly. To accelerate drying, replace a portion of the oil (e.g., linseed) with a 1:2 dammar-turpentine solution. Chemical description: Pigment Orange 36, C.I. 11780. CAS No. 12236-62-3, EINECS 235-462-4Resistance to alkali: 5 (1 is bad, 5 is best)Resistance to lime: 5 (1 is bad, 5 is best)Resistance to acid: 5 (1 is bad, 5 is best)Lightfastness - thinned: 8 (1 is bad, 8 is best)Lightfastness - medium: 8 (1 is bad, 8 is best)Lightfastness - concentrated: 8 (1 is bad, 8 is best)ColorIndex: PO 36.11780Suitability: Acrylics, Tempera, Watercolor / GouacheColors: Orange, RedForms: powderSolubility in water: insoluble
