With the increasing development of the domestic printing and dyeing industry, textiles have become indispensable products in daily life. It is understood that the standards for textiles in China have also been improved. Among them, the color fastness in the dye program, abbreviated as color fastness, is highly concerned by the general public.

The so-called color fastness refers to the ability of the dye used in the dyeing process to maintain its original color state due to external and chemical factors, which is commonly referred to as fading. Most of the current color fastness testing methods are simulated or comprehensive tests based on the environment and conditions of action, and the fastness level is evaluated based on the color change of the sample after the test and the staining of the adjacent fabric. What is more unique is that the color fastness to light is rated using a blue standard, while the color fastness to dry cleaning is evaluated for solvent staining.

When grading color fastness, comprehensively assess the changes in the three color attributes. Changes in hue, brightness, and purity.

Hue refers to the appearance of a color. Among the three attributes, hue can be used to distinguish colors. According to the different wavelengths of light, colors have properties such as red, yellow, or green, which is called hue. Depending on the degree of light reflected on the surface of an object, the brightness of its color will vary. The degree of brightness of this color is called brightness. Purity refers to the degree of saturation of colors. The simpler the wavelength of the light wave, the higher the hue purity, and vice versa, the lower the purity.