Set of four opaque neutral gray inks! For the black & gray artist looking to create a smooth opaque gradation, these four inks are evenly spaced at 20%, 40%, 60% and 80% of black on the value scale. Color artists will love the neutral grays for toning down any color without a having a shift in color hue. Adding this set allows an artist to extend their color palette with a wider range of tones and shades.