Grey Scale
Grey Scale is a scale used to rate, by comparing with standard samples, the degree of color change or staining on another textile after a colorfastness test.
Contents6 sections
Definition and Overview
A grey scale is a tool and evaluation scale used to judge color difference by visually comparing the color change before and after testing with standard samples of different shades. It is mainly used in tests for colorfastness, that is, to confirm color durability against washing, friction, and similar effects.
For evaluation, there are scales for color change, which assess how much the test specimen itself has changed color, and scales for staining, which assess how much color has transferred to the attached white cloth or similar material. Neither is a name for the structure, material, or texture of a textile.
Evaluation Targets and Features
A grey scale for color change evaluates fading or discoloration of the specimen due to washing, perspiration, light, friction, and similar actions. A grey scale for staining evaluates color transfer to another fabric that contacted the specimen during testing. Generally, the higher the grade, the less color change or staining it indicates.
It is important to perform judgment under specified lighting and observation conditions. Because impressions can vary depending on the light source, surrounding colors, and the observer's perception, the comparison conditions with the standard samples are kept consistent. This is an evaluation related to how color appears, and it does not directly judge hand feel, thickness, elasticity, or shrinkage.
- Color change: evaluates changes in the color of the specimen itself.
- Staining: evaluates color transfer to attached cloth or other materials that came into contact with the specimen.
- Evaluation target: varies by test purpose, such as washing, friction, perspiration, or light resistance.
Main Applications
It is used for quality control, material selection, and inspection of the dyeing and printing of textiles and products. It is checked on a wide range of apparel where color transfer during washing or wear can be a problem, such as shirts, cut and sewn knits, denim, uniforms, sportswear, and linings.
For dark-colored items, color-blocked items, and products combined with light colors, staining evaluation becomes especially important. In applications that require light resistance, test results for light-induced color change are also useful in early-stage planning for material comparison and label review.
Selection and Handling Notes
The required performance is set according to the application, wearing conditions, washing method, and the colors combined. Do not judge pass or fail from the test name alone; clearly define in the specification sheet the test conditions and evaluation targets required for the product, such as dry and wet friction, or color change and staining during washing.
Grey scale ratings do not indicate shrinkage rate or whether sewing is possible. When using product washing, after-processing, heat or steam during sewing, or light/dark color combinations, check for color transfer or discoloration in a state close to the finished product. Discoloration during storage due to light, moisture, or gas also needs to be considered separately.
Differences from Similar Terms
Colorfastness refers to the overall performance of how well color withstands washing, friction, perspiration, light, and similar factors. A grey scale is the comparison scale used when judging color change or staining within that performance. Therefore, the grey scale itself is not the colorfastness performance of a textile.
Light fastness, wash fastness, and rub fastness are test and performance items for specific actions, respectively. A grey scale may be used to evaluate color change or staining in each test, but the test methods and evaluation items are not the same.
Frequently Asked Questions
What is the difference between the grey scale for color change and the grey scale for staining?
The grey scale for color change judges how much the color of the specimen itself has changed after testing. The grey scale for staining judges how much color has transferred from the specimen to another material such as attached white cloth. Use them according to the phenomenon you want to confirm.
If the grey scale grade is high, can it prevent all color fading problems?
Not necessarily. The evaluation result indicates performance under the target test conditions. Because the factors causing color change differ in washing, wet rubbing, perspiration, light, and similar conditions, check multiple test results according to the product's application, color combination, and care label instructions.
