Class name for a group of organic azo pigments made by coupling 3-hydroxy-2-naphthoic acid to various amines and forming the barium, calcium, strontium, or manganese salts. They have bright shades ranging from yellow-red to deep maroon, good light and heat resistance, nonbleeding in vehicles and solvents, and good opacity. They are widely used in printing inks, paints, enamels, lacquers, rubber, plastics, wallpaper, textiles, floor coverings, and crayons.