Inspired by Nature: Why Cork Fabric Is The Most Sustainable Fiber There Is

Marisa Simoes for Global Garbs Magazine, Issue 03

Founder, Carry Courage

If you’ve spent any time in the sustainable fashion space, chances are you’ve noticed several different materials that are commonly used. Organic cotton, hemp, and bamboo are a few that I’ve seen used quite a bit. Today I’m going to share about a less commonly used fiber, cork fabric.

Before I embarked on my own sustainable fashion journey, I was drawn to cork fabric’s natural beauty. After becoming aware of the global fashion pollution pandemic, I began to do a lot more research into circular design and the foundational aspects of different fibers; from how they’re made, to what type of impact they’ve had on the planet and the people involved in their production. I have learned that not only is cork fabric beautiful, but it’s also one of the most sustainable fibers. 



In The Field: Harvesting the Cork Oak Tree

Cork fabric begins its life as the bark from the Cork Oak tree, which is native to the Mediterranean basin. The tree must be a minimum of 25 years old before it can be harvested for the first time. After its first harvest, it takes about 9 years to re-grow enough bark for a second harvest. This process can be repeated for an average of 150 years!

Harvesting of cork is a skill that is only done by experienced craftsmen. It involves opening the bark with an ax, separating it from the trunk, carefully extracting it from the tree so it does not split, and marking it with the year it was harvested. After harvest, the cork is stacked in piles outdoors, where they remain exposed to the elements to cure for 6 more months. 

At the Processing Facility: Turning Cork Bark into Cork Fabric

After harvesting, these large bark planks continue on the process by being boiled in water, which kills all the fungus and bacteria off the bark. This is an important step because the trees are never exposed to any pesticides, which means that mold and bacteria can easily grow and cause an irregular color and structure in the cork. The heat and weight of the boiled cork also help to flatten it once it is re-stacked. After boiling, the cork needs to rest and dry for an additional 3-4 months.

Following the drying period, the cork bark pieces are cut into uniform shapes. Then, they are sliced into 3 layers. Only the middle layer is used for cork fabric. The outer layers are used for other cork-based products. This middle layer is then sliced again, this time into very thin sheets. These thin sheets are then “glued” together using heat. No glue is actually used, as the resin in the bark, when heated, is strong enough to bond the thin sheets together.

These thin pieces of cork will now need a backing to make them pliable and sewable. Some typical backing for cork fabric includes cotton, polyester, or polyurethane. Our backings utilize a combination of all three to make a felt-like backing that is soft, smooth, and sewable. A natural, water-based glue is applied to the backing, and the thin cork sheets are applied to the backing by hand. The cork bark’s position on the backing can result in different visual effects in the fabric. After all the layers are assembled, a non-toxic sealant is applied to prevent liquids from entering the fibers. 



Circular Design Benefits of Cork Fabric

When sourcing materials for our products at Carry Courage, I always look at where it came from, how it was made, and where it will go when it’s disposed of. Although I never like to think my products will end up in a landfill, the fact is that someday, somewhere, they will be disposed of. This is why the concept of circular design is so important to me. Disposable fast fashion should not have a place in our economy. 

Cork fabric is a truly renewable material throughout its entire life cycle and easily fits into a circular economy system. Besides contributing to the reduction of CO2 through harvesting the bark, requiring only minimal natural resources to grow, and maintaining natural forest wildlife habitats, it is ultimately biodegradable and recyclable at the end of its lifetime. 

Cork fabric is a unique material and one that is not yet commonly used in mainstream fashion. I actually stumbled upon cork fabric before I migrated into a more sustainable brand approach, simply for its beauty. After researching the process cork goes through to become a fabric, we can also see how it benefits our planet and future generations living on it. The topics of circular design and sustainable fashion can be extremely complex, but my hope is that you have learned more about how products made with cork fabric are making a positive, purposeful impact on the Earth.

Click here to download the full issue of Global Garbs Issue 03

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