Sennelier oils have a jewel-like brilliance and high tinting strength. The paint is ground very slowly and carefully into safflower oil. The pure pigment is first 'pulverised' and then processed to an 'Extra- Fine' powder. The point of this process is to optimise the pigment’s so-called ‘refractive-index’. Safflower oil has a slower drying time compared to linseed oil, so Sennelier oil colours dry a little more slowly. Finally these paints represent great value for money when compared to many of their peers.