Faber Castell Polychomos are the finest oil-based colour pencils on the market. Each pencil has a 3.8mm lead which is coloured with high-quality artists' pigments suspended in an oil-based binder. This lead is bound to its casing of Californian cedar-wood, which renders it exceptionally break-resistant. It is water-resistant, smudgeproof and has exceptional covering power, though it will also sharpen to a very fine point for detailed work. The full range includes 120 colours which are graded good, very good or maximum for light-fastness.According to Faber Castell's light-fastness scale, this pencil is graded good (*).pdf=POLYCHROMOSArtistColorPencils.pdf Polychromos Artist Color Pencils colourchart.