Studio XL colours are intense and permanent, with great resistance to thermal and photo-oxidation. Viscosity is constant from one colour to another and the pigments are chosen to provide similar colours to the extra fine oils, while providing excellent value for money. Can be used with all oil painting mediums and diluted with mineral spirits. For application on all traditional oil painting surfaces, such as canvas, card and wood. Dries to the touch in 3-6 days.