The finest watercolour, offering the widest choice of pigments and highest possible permanence. Since 1832 when Henry Newton and William Winsor introduced the first moist water colours to the world, much of their reputation for supreme quality has stemmed from the Artists Water Colour range. Each colour of the Winsor & Newton Artists' Watercolour range has been selected and formulated to offer the greatest choice so that artists can use a unique palette that best suits their work. Colour number: 644 Series number: 1 Chemical description: Titanium dioxide Colour index name: PW 6 Colour index number: 77891 Permanence rating: AA ASTM lightfastness rating: I Transparency/Opacity: O