I never met a color I didn’t like.
– Dale Chihuly
Dyeing, which has been covered in previous posts, is the process of adding color to textile materials. There are several ways to dye a textile product and each has advantages and disadvantages. The most common obstacle is Color Matching Problems.
Consumers demand appealing colors and wider color choices. Purchasing decisions are now based on the item’s fashion and color. Thus it is crucial to overcome color issues in your products.
Let’s look at the methods to add color to the fabric before going into details of color matching problems.
Dyes can be added at any step in manufacturing textile goods and dye can be applied to the fiber, yarn or fabric. The type of the fabric will determine which dyeing method is better for that specific garment based on its chemical structure and dye uptake properties (Need more info about fiber structures and dyeing? Look here and here).
In general, we can categorize dyeing method as:
- Direct Application: As you can understand from its name, this method offers a dyeing process without adding any agents. In other words, a dye is directly applied to the fabric. It is often used for dyeing cotton. Direct dyes, which are applied directly from an aqueous solution to the fiber, is the most common example.
- Stock Dyeing: This is the method to dye fibers or stock before it is spun into yarn (you can see the difference between fiber and yarn in the picture).
- Yarn Dyeing: This is the method of dyeing yarns before woven or knitted into fabrics. It is preferred to create unique patterns, stripes and etc. It is one of the favorite techniques in the art society.
Yarn dyeing inspiration for artistic souls: Pinterest
What are the dyeing problems?
Besides personal faults and missing steps during the dyeing process, there still might be some issues based on the nature of the fiber or based on dye you choose.
Crocking: Transfer of color when fabric rubs against something.This occurs when dye molecules are not adhered to the fabric strictly and properly.
Bleeding: Sometimes your cloth or a piece of fabric that you work on gets wet and dye leaches out. Sometimes it happens when you wash your clothes and in the end you get a mess in the washing machine. Well, that is the bleeding issue that we are talking about here. It is probably the most annoying one since not only that particular pieces loses its color depth, but also the other pieces in the washing machine will be ruined.
Fading: This is basically fabric’s lost of much of its dye and it results changes in depth, shade and brightness. Darker the color, more fading occur.
Some of the general reasons cause these problems above:
- Using wrong dye for the material (Do not forget! There are different dyes for different fibers).
- Picking wrong dyeing technique.
- Using excessive amount of dye. This results leftover dyes in the product which have not been adhered strictly. (Be careful during rinsing out after dyeing. Do it multiple times to prevent any future problems).
- Not using a fixing agent when it is necessary, such as Mordant (↓ continue reading for information about Mordant).
- Bleaching, heat, sun etc.
Mordant: This is an agent used for fixing dyes on fabrics. Some common mordant include tannic acid, urine, sodium chloride (salt), chromium, copper, iron, iodine, potassium, sodium, tungsten and tin.
Colorfastness: This is the resistance of a material to fading. The material should be tested for colorfastness before using bleach or other products. Also, it should definitely be tested by the producer before even selling the textile product. Because, according to the results of colorfastness tests, producers put information to care labels.
↓↓↓ Want to learn more about Colorfastness Tests in Textiles? Keep reading ↓↓↓
- Lightfastness, wash fastness and rub fastness ate the 3 main forms of colorfastness that we need to look at.
Lightfastness: Resistance to fading when exposed to light.
Wash fastness: Resistance to fading when washed. Fastness to the problems occurred during washing.
Rub fastness: Resistance to crocking.
- Aspects that effect the colorfastness property of a fabric:
The chemical structure of the fiber. For example, cellulosic fibers show good resistance to fading when dyed with reactive or vat dyes. Protein fibers need acid mordant with reactive dyes to show good fastness properties.
The chemistry of the dye molecule. For example. If the dye molecule is large, it will be tightly held inside the fiber. Thus the fastness will be better.
The bond’s strength between the dye and the molecules of fiber.
The amount of dye present in the fiber (depth of shade). A deep shade will be less fast than a pale or light shade.
The presence of other chemicals in the material (contamination).
- There are test methods that we, textile scientist, follow to evaluate colorfastness. AATCC is the best known for its standardized test methods and evaluation procedures.
Gray Scale for Staining – used for evaluating staining on undyed textiles. Place the specimen of the stained fabric side by side with a piece of the unstained fabric oriented in the same direction in the Color Matching Cabinet so it can be viewed at a 45-angle. Place the Gray Scale along the edges of the test specimen and unstained fabric with the junctions of the Gray Scale and the fabrics aligned. Compare the differences in the two fabrics with the scale and assign a grade. A grade of 5 is given only when there is no difference in color or contrast between the tested and untested. Each person in the group needs to assign a grade to each specimen and then the group will come up with an average for their fabric for each test.
Gray Scale for Color Change – used for evaluating color loss or change during exposure to laundering. Place a piece of the original, untested fabric and the tested specimen side by side in the same plane and going in the same direction in the Color Matching Cabinet so it can be viewed at a 45-angle. Place the Gray Scale along the edges of the two fabrics, tested and untested. Compare the visual difference between the two fabrics to the differences represented by the Gray Scale. Determine the grade by figuring out the grade that corresponds with the most appropriate change in color. A grade of 5 is given only when there is no perceived difference in color or contrast between the original and the tested specimen. Each person in the group needs to assign a grade to each specimen and then the group will come up with an average for their fabric for each test.
- There are also standards that you need to follow, developed by ASTM.
D2096-11: Standard Test Method for Colorfastness and Transfer of Color in the Washing of Leather
This test method covers the determination of the colorfastness of colored leathers, with or without a surface coating. The leathers to be tested are of the type normally expected to withstand frequent laundering.