A Guide to Denim Washes and Techniques

Iconic and deservedly so, let’s start our discussion of this much-adored fabric with a little history. Ever since the inception of “blue jeans” in the 1870s as workwear for miners and cowboys (thank you, Mr. Levi Strauss, we tip our hat to you), denim has evolved to become the most popular fabric in the world today. It’s durable, wrinkle resistant, long lasting and looks great with practically anything.

Designers are forever finding ways to incorporate denim into collections that aren’t just about “jeans”. That said, with so many fabric techniques and washes to choose from, denim designers are also finding ways to make the tried-and-true jean style even more desirable. Button- or zip-fly, baggy, skinny or boyfriend, dark or vintage-washed, there are few fabrics that lend themselves to more unbridled creativity than denim. And the consumer just loves it.

In fact, Revuz says: “The average American owns seven pairs of blue jeans, and approximately 450 million pairs of jeans are sold in the United States per year. The 2019 worldwide denim jeans market is estimated at over 60 billion dollars.” Yes, you read that right, 60 billion! They go on to say, “Over 300 million pairs of women’s jeans were sold in the U.S. alone. Online sales are growing in the denim jeans market, with a 32% increase in purchases made through e-commerce channels.”

Most denim comes from the mill “indigo dyed.” The dyeing happens through a fermentation process by breaking the dye molecules into simpler substances. In this stage, it dissolves in the solution and the fabric yarn gets dyed. At a later stage, when it is taken to oxidation by exposing it to air, the beautiful, deep and rich blue of indigo is achieved.

But what happens next is up to you!

Stone Wash

Towards the end of the seventies, pumice stones were discovered to accelerate the aging process of indigo dyed denim garments. Thus, stone washing was born. Stone Wash is the most common and basic process for producing a washed-down look on denim garments. In fact, almost every denim garment you see today has some version of stone wash (unless it’s made from a raw, rigid denim).

The stone washing effect can be as gentle or extreme as you like. The degree of the “wash-down” effect depends upon several factors – the size of the stone, stone ratio, liquid ratio, duration of treatment, garment load, etc. Different stone wash names like sand wash, golf ball wash, micro wash and micro-sand wash refer to the use of various size of pumice stones.

Acid Wash (aka Moon Wash, or So Totally ‘80’s)

Acid washing or “ice washing” is usually done by dry tumbling the garments with pumice stones presoaked in potassium permanganate solution, resulting in a localized bleaching effect in a non-uniform sharp blue/white contrast on the denim.

Unfortunately, this is probably the least environmentally-friendly of all the denim treatments. The manganese dioxide formed out of the potassium permanganate must be removed from the fabric after the process. Furthermore, hypochlorite (also used in the process of acid washing) is a harsh chemical that can damage cellulose, resulting in severe strength loss, breakages and pinholes at the seams and pockets. And since hypochlorite is a hazardous chemical, it must be disposed of properly. Sadly, that doesn’t always happen.

Rinse (or Mill) Wash

Rinse wash is the simplest among the washing applications used in denim fabrics. If you want the denim to retain the most indigo shade possible, and yet offer a little softness, this is the wash for you.

In this type of washing, the fabric is washed in cold or warm water for a short or medium term, depending on the amount of softness – in both color and appearance – is desired.

Since rinse washing is a light washing process, it does not cause major changes on the physical properties of the fabrics. However, it can (and most likely, will) cause some shrinkage. Don’t forget, even the smallest changes in fabric after washing have great consequences on the sewn product.

Enzyme Wash

Enzymes have opened up exciting new possibilities in denim finishing by increasing the variety of finishes available. What’s more, using enzymes it is now possible to fade denim to a greater degree without running the risk of damaging the garment.

Enzymes are molecular proteins which accelerate biochemical reactions within a short span of time. The most commonly used enzymes in the textile industry include alpha amylases, proteases, catalases and cellulases. As the name suggests, they degrade cellulose.

This technique has some environmental advantages over stone washing. The use of cellulases instead of pumice stones prevents damage by abrasion to washing machines and the garments, eliminates the need for disposal of the used stones, and improves the quality of the waste water.

What’s more, the load of garments may also be increased by as much as 50% since stones are no longer added. Therefore, less water is used overall and more fabric is treated at the same time.

Bleach Wash

In bleach wash, a strong oxidative bleaching agent is added during the washing, with or without pumice stones. The purpose of the bleaching is to decolourize the dark blue shade by destroying the indigo dye molecules with oxidative bleaching chemicals.

While bleach wash is very effective, it does come with a bit of an impact to the fiber and the environment. It damages the fabric and there is emission of polluted wastewater.

But it’s not all bad news for this popular wash. Ecologically less harmful methods such as laccases, potassium permanganate, potassium persulfate, sodium caustic and peroxide have been tried, with varying results. So ask your fabric wash house about which method they use!

Mechanical Techniques

• Bullets: This is one of the more creative techniques we’ve seen. It literally involves shooting at the garment with bullets. As part of the proof, some jeans manufacturers incorporate the empty bullet cartridge in the trouser pocket.
• Scrubbed: The surfaces of the trousers are scrubbed with brushes in this process, to effect suede and partially fluffy appearance.
• Razor, sandpaper and Dremels:  Exactly as it sounds!!

So, if you’ve read this far, we assume you’re looking to cash in on the denim market. The trick is to make your denim collection stand out from the other 450 million pairs of jeans sold each year. One way to do that is to take advantage of the myriad of ways you can approach this much-revered fabric! We hope this discussion has inspired you to do just that!

We’d love to hear about your plans for your next collection. Feel free to reach out to us at https://tegintl.com/get-in-touch/ or give us a call at 800-916-0910.

RESOURCES:

https://coats.com/en/information-hub/Denim-Wash
https://www.revuze.it/blog/denim-jeans-market-report/
https://denimmanufacturer.net/what-does-rinse-wash-jeans-mean/