Reactive Blue 21 is a vinyl sulfone (VS) reactive dye based on a phthalocyanine chromophore. This chemical structure is responsible for its exceptionally brilliant, clean turquoise shade, a colour difficult to achieve with other dye classes. It is a premium choice for dyeing all types of cellulosic fibres where a vibrant, high-impact turquoise is desired. The VS reactive group ensures a high level of fixation and good all-around fastness properties.
