Water Mixable Oil Colour has a specific thinner for the range. The purpose of Artisan is to be able to avoid the use of hazardous solvents. Although the water is suitable as a diluent for the colour, its speedy evaporation can make the colour thicken upon the palette much quicker than conventional oil colour would when used with turpentine. To help with this, Winsor & Newton have developed a thinner to dilute Artisan colours. This can be used instead of water or combined with it to provide a more oily consistency.