At M. Graham, we believe we have a responsibility to every artist that chooses our color. We select the finest pigments and use only the very best vehicles. We take the time and expend the effort to make color with greater clarity and superior working properties. Our commitment to the artist extends to their environment. M. Graham is free from solvents in our workplace. You can free your studio of dangerous solvents as well. Using walnut oil to clean brushes is a natural way to remove color without creating a solvent hazard. Made in the USA. Set includes one each Azo Yellow, Naphthol Red, Ultramarine Blue, Phthalo Green and Titanium White plus free 2 oz. Walnut Alkyd and 2 oz. Walnut Oil Medium.