C9, Aromatic Resins are so named because they are generally polymers of nine-carbon aromatic monomers. They are based on aromatic feed-stocks that undergo very little refining prior to the polymerization of the resin. They are usually dark in color within typical Gardner color of 6 to 10 (dark yellow to dark brown). They are used mainly in EVA-based adhesives, contact adhesive for footwear, printing inks, sealants, and paints. C9 liquid resins are especially useful in flooring adhesives. As a class, C9 resins have a distinctive aromatic odor. There are two sub-categories of C9 aromatic tackifiers, each with distinctive properties.