The color of a fabric is an important factor in its appearance and appeal. However, color can also be a source of frustration for consumers and manufacturers alike. When fabrics fade or bleed, it can be disappointing and even costly. That’s where fabric color fastness comes in. In this article, we will explore what fabric color fastness is, why it matters, and how it can be measured and improved. Whether you are a consumer looking for long-lasting clothing or a manufacturer looking to ensure the quality of your products, this is the ultimate knowledge you want to know about fabric color fastness.
What is the definition of fabric color fastness?
Fabric color fastness is a measure of how well a fabric retains its original color when exposed to various external factors, such as washing, sunlight, or rubbing. This property is important for maintaining the aesthetic appeal of a garment or textile product over time. A fabric with high color fastness will retain its original color longer and be less prone to fading or discoloration.
What factors affect colour fastness？
Before we delve into the different types of color fastness, it is essential to understand the different factors that affect the color of a fabric. These factors include:
- The type of dye used: Different dyes have varying levels of color fastness. Some dyes are known to fade quickly, while others are more resistant to color fading.
- The type of fabric: Some fabrics are more susceptible to color fading than others. For example, natural fabrics such as cotton and wool tend to be more colorfast than synthetic fabrics like polyester and nylon.
- The type of finish applied to the fabric: Different finishes, such as a wax or resin finish, can affect the color fastness of a fabric.
- The type of environment the fabric is exposed to: Environmental factors such as sunlight, washing, and rubbing can all affect the color of a fabric.
Different types of fabric color fastness
Now that we have an understanding of the factors that affect the color of a fabric, let’s take a closer look at the different types of color fastness.
- Light fastness: This refers to the ability of a fabric to retain its color when exposed to sunlight. The light fastness of a fabric is determined by a standardized testing method where a piece of fabric is exposed to a specified amount of light for a specific period of time. The color change of the fabric is then measured and compared to a standard color change to determine its light fastness.
- Wash fastness: This refers to the ability of a fabric to retain its color when exposed to washing. The wash fastness of a fabric is determined by a standardized testing method where a piece of fabric is washed in a specified detergent solution for a specific number of times. The color change of the fabric is then measured and compared to a standard color change to determine its wash fastness.
- Rub fastness: This refers to the ability of a fabric to retain its color when exposed to rubbing. The rub fastness of a fabric is determined by a standardized testing method where a piece of fabric is rubbed against a specified surface for a specific number of times. The color change of the fabric is then measured and compared to a standard color change to determine its rub fastness.
Testing standard for color fastness of fabrics
The ISO 105-C06 test is widely used in the textile industry to evaluate the colorfastness of fabrics. This test is based on the principles of photochemistry, which is the study of the interaction between light and matter. When fabrics are exposed to light, the color pigments in the fabric can break down and fade, resulting in a loss of colorfastness. It is designed to simulate the effects of light on fabrics, allowing manufacturers to determine the level of colorfastness of their products.
Using a standard light source to expose the fabric to a controlled amount of light is the main method of this test. The light source used in the test is typically a xenon arc lamp, which produces a spectrum of light similar to sunlight. The fabric is then placed in a viewing box, where it is assessed for colorfastness by comparing the original color of the fabric to the color of the fabric after exposure to light. The test results are typically reported on a scale from 1 to 5, with 5 being the highest level of colorfastness.
The ISO 105-C06 test is typically performed on fabrics that have been dyed or printed, as these fabrics are more likely to lose their colorfastness when exposed to light. The test is also often performed on fabrics that are intended for outdoor use, as they are likely to be exposed to more intense light than fabrics used indoors.
Which third-party organizations can test the fabric color fastness?
There are several third-party organizations that can test the color fastness of fabric. Some examples include
- American Association of Textile Chemists and Colorists (AATCC)
- Textile Institute (TI)
- Société Générale de Surveillance (SGS)
- Bureau Veritas (BV)
- Intertek (ITS)
It is important to choose a reputable and accredited organization to ensure the accuracy and reliability of the test results.
How to evaluate color fastness by yourself?
However, we can also do the testings by ourself at home if those professional services from above organizations are not necessary.
One simple test is to rub the fabric against a white cloth or piece of paper. If the color from the fabric rubs off onto the white cloth or paper, then the fabric is not colorfast.
Another test is to wet a small, inconspicuous area of the fabric with water and then rub the wet area with your fingers. If the color from the fabric comes off onto your fingers, then the fabric is not colorfast. Additionally, you can perform a lightfastness test by exposing the fabric to direct sunlight for a few hours and then checking to see if the color has faded or changed. If the fabric has good colorfastness, the color should not fade or change after being exposed to light.
It’s important to note that colorfastness can vary depending on the type of fabric and the specific dye used, so these tests are not foolproof. It’s always best to check the care instructions on the fabric or consult with a professional to determine its colorfastness.
How to improve different types of color fastness?
There are several methods that can be used to improve the color fastness of a fabric. These methods include:
Using high-quality dyes: As mentioned earlier, the type of dye used can affect the color fastness of a fabric. Therefore, using high-quality dyes that are resistant to fading can improve the color fastness of a fabric.
Pre-treating the fabric: Pretreating the fabric before dyeing can help to improve its color fastness. This can be done by applying a special finish or by washing the fabric in a solution that helps to improve its color retention.
Using a special finish: Applying a special finish, such as a wax or resin finish, to the fabric can help to improve its color fastness. These finishes create a protective layer on the fabric that helps to prevent color fading.
Storing the fabric properly: Proper storage can also help to improve the color fastness of a fabric. This means keeping the fabric away from direct sunlight and other environmental factors that can cause color fading.
Conclusion
Color fastness is an important factor to consider when choosing fabrics. It determines the ability of a fabric to retain its color when exposed to different environmental factors such as sunlight, washing, and rubbing. There are several methods that can be used to improve the color fastness of a fabric, including using high-quality dyes, pre-treating the fabric, applying a special finish, and storing the fabric properly. Understanding the different types of color fastness and the factors that affect it can help you make informed decisions when selecting fabrics for your projects.
