Widely used in the textile industry for dyeing cotton, wool, and silk fabrics, providing a strong navy blue color with good wash fastness. Commonly applied in batch dyeing processes for cellulose fibers due to its high affinity and uniform shading properties. Also utilized in paper printing and ink formulations for consistent color reproduction. Limited use in biological staining due to moderate toxicity, but occasionally employed in histology for demonstration of certain cellular structures. Its application in industrial dyeing is favored where high color intensity and lightfastness are required.