Holy macaroni, I thought I was going to break my brain trying to get to the bottom of the truth about cupro…mostly because I had to dig (and dig some more) to get past the a mountain of articles and blog posts that were all referencing the same ChatGPT sources. It was rough.

But here it is! This is part 11 of 12 in the synthetic fabrics series…yep, only one left to go and it’s a banger…ELASTANE! Coming next week!


And that brings me to this:

I’ve gotten a lot of messages pushing back on my assertion that no fabric/yarn lets us overconsume without repercussions for the planet and every living thing on it.

But I’m standing by it.

Sure, some fabrics are more sustainable than others…but when we’re churning out and consuming massive amounts of anything, it all becomes destructive. That’s especially true with an industry that prioritizes profitability over everything else.

Crops for fabric take up farmland, use up water, and rely on exploited labor. Animal fibers aren’t exempt either: scaling up wool, alpaca, etc, to meet the current consumer demand still requires land, water, and in a profit-driven system, that leads to deforestation and abuse of animals. Seriously, ask me about the video PETA sent me this summer about animal abuse in a farm allegedly used by Icebreaker.

We have to change up our habits. Period. We cannot continue to buy more clothes than we need, wear them a few times, then buy some more. There is no “green” fabric that cancels out overconsumption. The good news? All of you are already doing that! We just need to get more people involved (and we WILL)!

Meet cupro…

Cupro can refer to two things (and the distinction is important):

1. a shorter, cuter name for “cuprammonium rayon.” Also sometimes called “ammonia silk” or just “vegan silk.” However, polyester fabrics are sometimes called “vegan silk,” too.

2. the Bemberg fiber (a type of cupro) made exclusively by Asahi KASEI Fibers & Textiles in Japan.

The difference here? Bemberg is made in a closed loop process that minimizes chemical use and adheres to safety protocols. The production process is very transparent.

Cupro , cupra, ammonia silk, and vegan silk are technically the same kind of fabric, but made under less transparent conditions by other factories.

Is it sustainable?

• The good news: cupro is made from cotton waste–either discarded t-shirts/other 100% cotton clothing or from linter (silky cotton fibers that are often discarded because they are too small to spin). Linter is a byproduct of cottonseed oil manufacturing. Minimizing cotton waste is a good thing because growing cotton requires a massive amount of water.

• The less-good news: The process of creating cupro requires some serious chemicals that are toxic to all living things if not disposed of properly.

Attributes of cupro (no matter how makes it):

• Silk-like hand feel, fine texture, sheer weight.

• A vegan alternative to silk.

• Biodegradable

• Highly flammable, ignites easily at temperatures above 180 degrees.

• When ignited it leaves behind a residue containing significant concentrations of copper.

   

How cupro is made:

• The cotton waste is mixed with ammonium and copper. The two elements, when combined with the cellulose of the cotton waste, turn into a new substance.

• This new substance is dropped into caustic soda and then extruded into strings using a spinneret.

• Next, these strings are dropped into a series of “hardening” chemical baths that remove the ammonia, copper, and caustic soda, while also solidifying the cellulose.

There is a lot of misinformation out there about cupro.

First things first: Cupro CAN be a pretty great sustainable fabric option if it’s made in a closed loop system, where chemicals are recovered and reused. However, the only manufacturer doing this is Asahi KASEI in Japan under the trademark Bemberg. This has somehow been translated across the internet as “the only company in the world making cupro is Asahi KASEI.” This is not true.

The vast majority of cupro is made in China. Producing it is VERY cheap because cotton waste is plentiful and priced to move! There is little-to-no visibility into most fabric production in China, so there is no way of knowing if these textiles are made ethically and responsibility.

Wait, there’s more…

Cupro is no longer produced in the United States because manufacturers could not meet basic air and water regulations.

The chemicals involved in cupro production are harmful for humans, animals, and plants. If they are disposed of properly, they are less problematic, but the lack of transparency in the supply chain means we don’t know what is happening to these chemicals.

To be sure about your cupro clothing, ask brands to confirm that they are using the Bemberg cupro.

Still, I am hopeful about cupro!

• Cupro CAN be made from post consumer textiles (assuming that they are 100% cotton).

• This means that with a proper closed loop system (like the one used by Asahi KASEI), cupro could be a good circular option for the world. It’s not perfect (after all, all of that manufacturing does require energy and generate emissions), but it’s a start.

• Also, manufacturing cupro is not as water-intensive as cotton production. It’s not a license to overconsume clothing, but it could at least make the industry a little but more sustainable.

Make your cupro clothes last!

• Hand wash or use the delicate cycle. Either way, wash with cold water.

• Avoid harsh wringing or twisting.

• Skip the dryer, and opt for air drying (either on a washline or on a drying rack)

• For wrinkles, iron on the lowest setting or use a steamer. Or just hang it in the bathroom while you shower!