High Strength Sulphur Black B521 Textile Dye

Reliable black shade for cellulose fiber dyeing

Sulphur Black B 521 is mainly used for dyeing cotton and other cellulose-based fabrics. It is suitable for applications where a stable black shade is required, such as denim, workwear, casual fabrics, and general industrial textiles. For buyers looking for a practical black sulphur dye for bulk production, this product fits standard textile dyeing needs well.

Solves the need for cost-effective dark dyeing in mass production

In textile manufacturing, black shades are often required in large volumes, so cost control and consistent performance are important. Sulphur Black B 521 helps solve this by offering a commonly used sulphur dye solution for deep black dyeing on cotton fabrics. Its listed strength of 160% / 220% also gives buyers flexibility when selecting a grade for different shade depth or process needs.

Balanced fastness performance for everyday textile use

According to the product sheet, Sulphur Black B 521 shows light fastness 5, fade 3–4, stain 4, and iron 2–3. This indicates a balanced fastness profile for many standard textile applications, especially where good resistance to light and practical day-to-day performance are required. This makes it suitable for products that need usable durability rather than specialty-level performance.

Attractive for buyers who value practicality and production efficiency

The key attraction of this product is not exaggerated novelty, but dependable industrial usability. It is a black sulphur dye intended for common textile processing, with clear technical indicators and a shade that matches mainstream market demand. For many buyers, this is more important than overly complex positioning, because production stability and repeatability directly affect order delivery and cost.

Why choose this product

Buyers may choose Sulphur Black B 521 because it combines a standard Black 1 classification, commercially useful strength options, and workable fastness data in one product. Compared with choosing an unknown or over-positioned alternative, this product is easier to understand, easier to match with regular cotton dyeing applications, and more suitable for customers seeking a straightforward black dye solution for industrial use.

Sulphur Black B 521 is a sulfur dye used for dyeing cellulosic fibers. As confirmed by the product label in the image, the product name is Sulphur Black B 521, C.I. No. is Black 1, and it is available in two strength specifications: 160% and 220%, allowing customers to choose according to their target color depth, processing conditions, and cost requirements.

Regarding colorfastness parameters, the product has a lightfastness rating of 5, indicating good lightfastness under normal use conditions, suitable for textiles requiring a certain level of black stability. The table shows a fading fastness rating of 3–4, a staining fastness rating of 4, and ironing-related indicators of 2–3. This indicates that the product possesses relatively balanced basic fastness performance, meeting the general application needs of cotton fabrics and industrial dyeing.

From an application perspective, the 160%/220% strength settings indicate that the product offers certain specifications, allowing different customers to flexibly choose based on their needs for deep black dyeing, mass production, cost control, and process matching. For companies requiring standard black dyeing solutions, this parameter configuration offers strong practicality and industrial adaptability.

Overall, the key features of Sulphur Black B 521 are: clear product classification, well-defined strength specifications, good lightfastness, and stable overall fastness. Therefore, it is more suitable as a standard black dyeing product for cotton and other cellulosic fiber materials, meeting the comprehensive requirements for color depth, stability, and basic durability in mass production.