Color Fastness: Learn How to Measure it and Several Techniques

Have you ever washed a brand-new shirt? Did it bleed its colors? This is not an exception. It occurs due to poor color fastness. What happens to colors when they have faded? It is important to know about color fastness. It keeps the fabric looking new as always. To manufacturers, it translates to quality products, and the consumers, it provides long-term satisfaction. This blog post discusses the methods that keep the colors bright, as well as measurement and other techniques.

2. What is Meant by Color Fastness?

Color fastness is the resistance of a material and stays vibrant or running. This is the case of the dyes or pigments that retain their original color. It does this when subjected to a number of conditions such as wetting, washing, or lighting. Other factors, such as heat, are also involved. The term originated in the year 191,6 and it is predominantly applied in the textile industry.

A fabric is colorfast when the dye doesn’t run or bleed. They must not evade the clothing because it is essential in the durability of garments, besides influencing the satisfaction of customers.

3. Why is Colour Fastness Important?

There are numerous reasons as to why colour fastness is important. It affects the quality of products and causes dissatisfied clients. There is a possibility of returning products whose fastness is not satisfactory. This will negatively affect the image of a brand. 3NH knows your issue and provides an answer to it by providing color measurement solutions to guarantee high quality.

It is good to know a fabric is colorfast and does not undergo changes in color. As an example, black and white fabrics are stitched. During washing, they are not to bleed. It is important to give proper washing instructions and, therefore, give a quality item, creating trust.

The manufacturers should make products that are fit to be used. They have to comply with international laws and undergo intense testing.

4. Factors Affecting Color Fastness

Color fastness is dependent on many factors. These may be external and internal. Let’s discuss each of them, respectively.

Internal Factors:

● Fiber type: The various fibers do not absorb dyes uniformly. Such fibers of nature, such as cotton, respond differently. Synthetics such as polyester are also different, and Polyester tends to be faster than nylon.

● Dye characteristics: The type of dye that has been applied is also relevant, and some dyes form very strong attachments to fibers. The other bonds may be of a weaker kind. The dye is influenced by the molecular structure of the dye. The bigger the molecules of dye, the faster they may be.

● Dyeing process: The way a fabric is dyed is very important. Adequate fixing of dyes makes them last. Poor rinsing may not fix the dye, and the dye may either migrate or fade.

● Pre-treatments and finishes: Pre-treatments and finishes, and fabric treatments can affect fastness. These are softeners and fixing agents that enhance fastness. Some others may reduce it.

External Factors:

● Light exposure: The light (sunlight and artificial light) can fade. The UV light fades dyes with time, the loss of color.

● Washing: The washing could cause fading due to washing. Also, it may lead to dye transfer. It needs to be avoided by water temperature and detergents.

● Rubbing (Crocking): There is also a possibility of a transfer of color as a result of friction. This occurs when the fabric is rubbed against another fabric. Dry rubbing and wet rubbing are evaluated. Fastness is often less in wet rubbing.

● Perspiration: The perspiration of the human being has chemicals and may react with dyes. It is particularly so with activewear.

● Chemicals: Being exposed to bleaches or other chemicals can considerably influence the color integrity.

● Temperature and Humidity: High temperatures will cause deterioration of dyes. Humidity, on the other hand, may also be responsible.

5. What Factors Determine the Level of Colour Fastness?

The degree of the color fastness is subject to various factors. This covers the strength of dye-fiber. Fabric structure and yarn construction matter as well.

One of the biggest determinants is the dyeing methods selected and the kind of dye. Stimulating factors are also significant, including external force and environmental conditions.

Good quality dyes are adsorbed by the fibers. There is fixation through optimized dyeing processes. The fastness can be made additionally using after-treatment, and also the selection of materials plays an important role. An example is that polyester and acrylic fibers are naturally resistant to light.

6. The Science of Color Measurement

The art of measuring color is known as colorimetry, and it measures human vision of color. This entails the measurement of wavelengths of light. Such instruments are used as spectrophotometers. They have a range of visible light that is measured by reflected light or transmitted light. Spectrophotometers are precise and assist in defining the colour of the sample.

Colorimeters are easier to operate, and they give tristimulus colors. These are the values that depict the eye's perception of color. Gloss meters are used to measure gloss on a surface and may produce a psychological influence on color. In light booths, a controlled light is provided, and the visual evaluation can be done consistently.

The precise color measurement is necessary. It makes production consistent. It aids in assuring product quality. 3NH deals in color measurement equipment and offers equipment such as colorimeters and spectrophotometers.

Such colour measurement instruments are important in textile, plastics, and paint. Their devices assist in determining the color fastness in an objective way.

7. Color-Fastness Testing: Overview and Importance

Color fastness tests identify resistance and put colors under test in unfavorable conditions. These are water, light, rubbing, and washing. The other common test is the perspiration test, which determines the durability of dyed goods. They will prevent extra returns.

Quality control is important to be tested. It guarantees the quality of products. There are international standards that include ISO (International Organization for Standardization) and AATCC (American Association of Textile Chemists and Colorists).

Common colorfastness tests include:

● Washing Fastness: Measures color retention after laundering.

● Light Fastness: Assesses color stability under light exposure.

● Rub Fastness (Crocking): Checks color transfer due to friction.

● Perspiration Fastness: Evaluates color resistance to human sweat.

● Chlorinated Water Fastness: Important for swimwear.

● Seawater Fastness: Relevant for marine textiles.

● Dry Cleaning Fastness: Assesses resistance to solvents.

● Saliva Fastness: Crucial for baby and children's wear.

8. What Fabrics Are Not Colorfast?

Some fabrics are less naturally colorfast, and most natural fabrics belong in this group. These are 100 percent cotton, linen, and ramie. Wool and rayon are also non-colorfast. On these materials, dyes are more likely to bleed or fade out.

The darker the shades are, the lower their fastness. This is contrasted to the lighter colors. There should be suitable dyes chosen by manufacturers and suitable dyeing processes as well. This assists in enhancing the color fastness of such fabrics.

9. What is Color Fastness Level 4?

The color fastness is usually rated and a scale of 1-5 is popular. Grade 5 is very fast. Fading is not evident. Grade 1 signifies extremely bad fastness, and it indicates considerable fading away or alteration.

Level 4 is good in most tests, such as when cleaning. It means slight fading or color shifting. This is appropriate to apply in most situations. In case of light fastness, however, an 8-level scale is applied. Level 8 is the fastest one. The worst one is level 1. Thus, level 4 has different meanings. It is a matter of what test is taken. Washing fastness is good in level 4. A grade 4 light fastness is not very good.

As an example, a washing fastness level 4 is a rating of a standard gray card. It implies very minor fading or staining. Light color fastness level 4 is usually required on home textile products.

10. What are the Grades of Color Fastness?

As stated, a grey scale is applied for the evaluation of color change and staining. The Grey Scale of Color Change rates fades and goes between 1 (maximum change) and 5 (no change). The Grey Scale of Staining scores the transfer of color and is ranked 1 (highest transfer) to 5 (no transfer).

The Blue Wool Scale is used in light fastness. It is between 1 and 8. Very low light fastness is represented by level 1. Level 8 means very high light fastness. The samples of fabrics are compared to the blue wool standards.

Generally:

● Grade 5: Excellent, no noticeable change.

● Grade 4: Good, minor fading or change.

● Grade 3: Fair, moderate fading or change.

● Grade 2: Poor, noticeable fading or change.

● Grade 1: Very poor, significant fading or change.

11. How to Fix Color Fastness?

To the consumers, it is easier to avoid color problems. New colored articles should first be washed separately and then washed in cold water. Use soft detergents and do not wash with bleach, and keep the garments in an inside-out position. This decreases friction and preserves colors.

Checking color fastness entails a number of measures. These techniques are used by manufacturers.

Improving color fastness involves several strategies. Manufacturers employ these techniques.

1. Selecting High-Quality Dyes: One should select dyes that produce strong bonds. Reactive dyes are covalently bound with fibers, and dispersed dyes are suitable for synthetics.

2. Optimizing Dyeing Processes: Fixation is done properly in order to support dyes. Fastness can be enhanced by means of after-treatments. The dye resistance can be improved by Cationic fixatives. Unfixed dyes must be well eliminated. The optimized process of dyeing would not be possible without proper washing and rinsing.

3. Applying UV Stabilizers: They form a protective coating. They prevent the dangerous UV rays, thereby increasing light fastness.

4. Using Fabric Finishes: Lab coatings can treat dyes. The Lamination with UV-blocking films facilitates fixing the color fastness.

5. Choosing Appropriate Materials: Some of the fibers have a natural inclination toward colorfastness. The light resistance is improved using the materials polyester and acrylic. Blends of them can be combined, too, and using advanced fibers also provides better resistance.

12. How Do Manufacturers Conduct Color Fastness Testing?

Manufacturers conduct rigorous testing and virtual tests in real-life conditions. They follow international standards such as ISO 105 and AATCC standards guide testing.

For example, ISO 105-C06 for washing fastness, ISO 105-B02 for light fastness, and ISO 105-X12 for rubbing fastness. These protocols ensure consistent and reliable results. This makes products to be of industry standards.

There are different types of tests performed with the help of special equipment.

1. Launder-Ometer / GyroWash

It is employed in the determination of the wash fastness. The samples are shaken using detergent and rinsed off, and dried. There is also the assessment of color change and staining.

2. Xenon Arc Light Fastness Tester (e.g., TruFade) / Weather-o-meter

It simulates natural sunlight. The samples of Fabric are illuminated. Fading is observed with time because, in this way, the long-term stability of color can be determined.

3. Crockmeter (e.g., CrockMaster)

This is an alternative to a CrockMaster; it determines rub fastness. The sample is rubbed off using a white cloth. The tests are done both in dry and wet conditions. The reaction to white cloth is assessed.

4. Perspiromete

Simulates human sweat exposure. Samples are treated with artificial perspiration and then pressed and heated. Color change and staining are observed over time.

5. Color Matching Cabinets

Another method that is used to conduct color fastness via regulated illuminations. They enable the eye evaluation of color to enable comparison of tested samples with originals.

6. Spectrophotometers and Colorimeters

They are objective color-changer measuring devices. 3NH offers such accurate measuring devices. Our devices assist both in measuring fine color changes and in high-accuracy assays.

13. How to Test for Colorfastness?

A simple test, which can be made at home, should be conducted by consumers. This establishes whether a fabric is colorfast. This easy test prevents accidentally washing the laundry.

1. Find an inconspicuous area: Choose a hidden seam or hem.

2. Dampen a white cloth: Use a clean, white cloth or paper towel.

3. Rub gently: Rub the wet cloth on the chosen area.

4. Check for color transfer: If dye transfers to the white cloth, the item is not colorfast. The dye will likely run when washed. If no dye transfers, the garment is colorfast and poses no risk of staining other items.

14. How is Colour Fastness Tested?

There are standard procedures for the colour fastness tests. These protocols simulate real-life exposure.

1. Wash Fastness

The wash fastness is carried out by preparing a composite sample. It has a textile and a multi-fiber lining fabric. This sample is dipped in a soapy solution.

It is subjected to agitation. Color change is determined after rinsing and drying. The stains on the lining fabric are also checked. Various methods are offered in the ISO 105-C series.

2. Light Fastness

Samples are subjected to light in case of light fastness. A sunlight simulator is a xenon arc lamp. There are blue wool standards exposed by the side. These standards disappear according to familiar rates. Comparison is made of the fading of the sample. This defines its light fastness rating.

3. Rub Fastness

Crockmeter is used in the case of rub fastness. The sample is rubbed on a test fabric. Dry rubbing as well as wet rubbing are executed. Transfer of color to the test fabric is evaluated.

4. Perspiration Fastness

In the case of perspiration fastness, samples are treated. They are subjected to man-made artificial sweat. These solutions may either be acidic or alkaline. The samples that have been treated are squashed and heated. Subsequent evaluation is done in terms of color change and staining.

Note: The comparison of all results usually takes place. Grey scale, blue wool scale are employed. This gives a scale rating. The larger the numbers, the faster the speeds.

15. Colour Fastness Techniques

Color fastness is enhanced through different methods. The methods keep textiles lively. They are not only able to meet consumer expectations, but they can also abide by the industry standards. Color fastness is a science that entails exact measurement to pioneering cures. It ensures the durability of beauty on our everyday fabrics.

● Advanced Dyeing Methods: Optimizing the dyeing curve. Temperature and pH control so that the dye is fixed and penetrated to the maximum extent..

● Post-Treatment Processes: Applying fixing agents. The anchor dyes can be anchored to the fibers by using cationic or anionic chemicals. Unfixed dyes are removed by soaping processes to avoid bleeding.

● UV Absorbers and Stabilizers: Using these chemicals on this fabric. They block the hazardous UV radiation and guard against the degradation of dyes.

● Nanotechnology: Coming up with nano particles of the dye that would enter the fibers more easily. They form better dye-fiber bonds.

● Digital Color Measurement: 3NH instruments allow the assurance of constant production of color. This minimizes batch-to-batch variations. Our spectrophotometers are precise tools in measuring color, and they also ensure the integrity of color.

● Pigment Printing Techniques: They do not absorb the pigments, but they get attached to the surface. This is capable of providing good fastness in certain conditions.

● Careful Blending: The usage of fibres with close dye affinities assists in the realization of homogenous fastness.

Conclusion

Color fastness is crucial because of the maintenance of the visual value of fabrics. When people learn the value of it, they can make informed decisions as manufacturers and consumers.

Fabrics can have high performance against fading, bleeding, and colour transfer with the right tests, methods, and quality of dyes. This provides measurements through instruments such as spectrophotometers. This gives an accurate measurement and dyeing technologies that all increase the durability.

Many approaches to fastness include the choice of the correct fibers, UV stabilizers, etc. Color fastness is a priority as it guarantees lasting quality, lasting vivid products that can satisfy the consumer and international industry requirements.