Winsor & Newton Artisan Water Mixable Oil Colours - Prussian Blue - 37 ML is magnificently designed to look and work just like traditional oil paint. The key difference between Artisan and conventional oils is its ability to thin and clean up with water. Artisan has been specifically developed to appear and work just like conventional oil colour. The depth of colour, buttery consistency, light fastness, opacity/transparency, performance and drying times of Artisan, allow artists to use this range for all oil colour techniques. Prussian Blue is a deep blue colour. It was made by German chemist Diesbach around 1704 making it the first synthetic blue pigment. It quickly gained favour as an alternative to genuine Ultramarine.