SKU: E Chartpak® AD® Marker Gray Set, 25 Markers The Gray set has cool, warm, and basic gray tones in gradient ranges. Experiment with blending and creating highlights and low lights with limited color families. This essential set will allow you to tone other AD Markers as well as create realistic shadows for car design, product design, and landscape architecture renderings. Chartpak's original xylene AD® Markers properties are unlike all alcohol-based markers common to the marketplace, and while they are compatible with one another, they perform very differently. They won't smudge alcohol-based pens including fine liners, they also work well over ballpoint pens and technical pens.