Acid Black 1, widely known as Naphthol Blue Black, is one of the most classic and versatile levelling acid dyes. It produces a deep, bluish-black shade and is valued for its good solubility, excellent levelling properties, and cost-effectiveness. As a disazo dye, it provides strong colour build-up on a variety of substrates. It is a staple workhorse in the textile and leather industries.
