Winsor & Newton Artisan Thinner Oil Medium is a better alternative to thinning colour than water. Although water is suitable as a dilutent for Artisan 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 issue, a thinner was developed. The Winsor & Newton Artisan Thinner Oil Medium provides a more oily consistency, which is preferred by some painters, plus there is less colour change than there would be when using water.