Direct Blue 86 is a water-soluble direct dye widely used in the textile industry for dyeing cellulosic fibers such as cotton, linen, and viscose rayon, providing a bright blue shade with moderate to good wash fastness. It is suitable for general apparel where high light fastness is not required. Commonly applied in continuous dyeing processes due to its good solubility and dispersion. Also used in textile printing, the manufacturing of colored paper products, and leather dyeing to achieve uniform blue tones. Occasionally employed in biological staining for microscopy as a temporary stain, though not a primary histological dye. Not recommended for products with frequent skin contact or children's items due to potential staining.