Have you ever noticed that garments that started out as the same color fade at different rates? You ordered two olive green items – a t-shirt and a pair of pants – that appeared to be identical colors but over time the t-shirt begins to fade while the pants remain closer to the day you bought them? Why is that?
The secret isn’t in the sauce, but it’s close. It’s more in how the individual ingredients come together. There are four major components that factor into how long color lasts and how true it stays to the original:
1. The type of fiber
2. The dye process
3. The tone
4. The finishing process
There is more to color than just the color. Different dyes adhere to different fabrics in different ways. For example, natural fibers such as cotton tend not to hang on to dye as well because the fibers are water soluble, meaning they are more prone to the effects of water and therefore likely to release the color more easily than a synthetic fiber, such as polyester, which bonds more easily and thoroughly. It’s not uncommon for a 100% cotton t-shirt to fade significantly after only one year of use, whereas a polyester polo may hold its color for several years before it starts to fade.
Many clothing items that will be exposed to a lot of light and harsh conditions, such as excessive sweat and heat, are made from synthetic blends so they will retain their color longer.
The Dye Process
Adding color to a garment can be done different ways, all of them involving dye. The most common and most expensive method is the vat dye, which involves submerging the material into a vat of color and letting it saturate all the fibers so the color permeates the entire fiber. This is the most expensive process, but it also gets the longest lasting results, as the color is infused throughout the material.
Another method is pigment print dying, where the dye is applied to one side of the material and might or might not soak through to the other side. Silk screening is a common application of this process, where a t-shirt, for example, is laid out and the dye is applied through a screen to the outside of the shirt only. Some of the dye might make its way through to the inside, but the process is designed to dye only one side. Color applied through pigment print dying tends to fade faster than vat dying.
One of the most intricate color processes is solution dye. This can only be done with synthetic fibers because the dye and fiber meet as liquids. Commonly used to dye Nomex flame-retardant materials and other garments comprised of multiple types of fibers, solution dye involves adding the dye directly to the liquid that will become the synthetic fiber. The now-combined liquid is then extruded and cooled to form the fibers to be weaved into the finished product. The main reason for this unique dye application is that aramid/heat-resistant fibers that make up a Nomex flight suit will not hold color from a vat or pigment print dying process as well.
Have you ever noticed that after a relatively short time all your black shirts and pants start to gray ever so slightly? Just ask a woman whose “little black dress” isn’t black anymore. Although the color itself doesn’t determine how much it fades, the darker the color the more noticeable fading becomes sooner. Navy blue, dark green, dark red, dark brown and black will appear to fade faster because they are deeper into the color spectrum than white, tan or other lighter colors. Rule of thumb: the darker the color, the more obvious the fade.
The Finishing Process
Some apparel, especially in the tactical world, is finished with an additional layer, such as Durable Water Repellant (DWR) that helps the garment resist water and stains by not permitting liquid to penetrate the fibers. The added – and originally unintended – benefit is that some DWR treatments also help reduce color fade, keeping the garment looking better longer.
Once a dye process is chosen, then it must be checked for quality to make sure the exact shade has been successfully and consistently attained. The tolerance for deviation is extremely tight.
“Not only does Propper use the highest standard dye processes and materials, we also have a military-standard evaluation process,” said Joe Ruggeri, Senior Vice President of Merchandising and Product Development. “We use the same specs for all our products, not just for our military customers.”
Color appears different under different lighting. To make sure quality standards are maintained, Propper uses a custom built “shade room” where material color processes are carefully scrutinized for quality control. The standards are so detailed that the lighting in the room is regulated to certain brightness levels to simulate outdoor light and indoor light. Even the angle of the table on which the fabric is laid and the shade of gray on the walls are regulated to maximize accuracy.
If the visual test is insufficient or inconclusive, a spectrophotometer is used to verify adherence to color standards by checking the material’s exact shade of color based on the predetermined standard versus the sample on the table.
Check the Tag
The next time you notice a shirt or pants that seem to be losing their original luster, or you notice that they look as good as the day you bought them, check the tag for the fiber content and try to guess which dye process was used.