Widely used in the textile industry for dyeing cotton and other cellulosic fibers such as linen and rayon, providing a strong blue color with good wash and light fastness. Commonly applied in the printing of textiles where consistent color and performance under light exposure are required. Also utilized in paper manufacturing to color paper products, offering uniform dyeing and compatibility with paper processing chemicals. Shows application in leather dyeing, especially for producing even shades on finished leather goods. Due to its ionic nature, it is sometimes used in laboratory settings, including biological research, as a staining agent for visualizing materials under microscopy.