[China Aluminum Industry Network] Due to the nature of the product itself and the requirements, dyes need to be selected when they are dyed. The choice of dyestuffs depends on the intended use of the product. Due to the different uses of the product, the requirements for dyeing products are also different. For example, outdoor products are often exposed to sunlight. Therefore, when dyeing, dyes with high light fastness should be selected. For products that are used at high temperatures, dyes that are resistant to high temperatures should be selected. According to the cost of dyes, dyestuffs are used. When selecting dyes, we must not only consider the shade and fastness, but also consider the cost and source of dyes and auxiliary agents used. For higher-priced dyes, other dyes that can dye the same effect should be considered as substitutes, such as domestic textile dyes, to reduce production costs. The color selection of dyes, when it is necessary to fight color, the use of dyes should pay attention to their composition, solubility, color fastness, dyeing rate, consumption rate, PH value and other properties. Due to the different dyeing properties of various dyes, the dyeing effect is often influenced by temperature, solubility, pH, etc. during dyeing. Therefore, when performing color matching, dyes with similar properties must be selected, which can be beneficial to the control of process conditions and the stability of dyeing quality. If the composition of the dye is not well understood, it is preferable to use a dye that is dyed by the dye supplier.