SeaCell: The Ultimate Guide

Summer Sweaters Made From Seaweed

We made our new limited edition summer sweaters, the Big Sur, from seaweed... as in the stuff that grows in the ocean!

Towering underwater like redwoods, seaweed grows vastly without exhausting arable land and fresh water. The material from these marine plants is ecologically sustainable and 50% more breathable than cotton.

We spent the last year perfecting a summer sweater, and a big part of our time was testing new material blends. In our long search, we kept coming back to a seaweed-based material called SeaCell. It’s arguably the most sustainable material on Earth.

We've got you covered if you’re curious how we can create a clothing material from seaweed. We answer all of your questions in this guide, and before you know it, you’ll understand why we choose SeaCell for our line of summer sweaters.

What Is SeaCell?

Technically speaking, SeaCell is a type of Lyocell, which we’ll get into a bit later in this guide, but generally, Lyocell has 2 defining characteristics:

• It’s made by reconstructing cellulose (plant cells) and then spinning it into fibers that can be blended with other materials like cotton and wool or spun on its own into yarn.
• It’s made in a “closed-loop.” Closed-loop means that the production process does not release solvents into the environment, unlike viscose.
• An organic solvent is used throughout the entire closed-loop process, and the Forest Stewardship Council has recognized the solvent as non-toxic.

SeaCell combines two different plant fibers, seaweed (obviously) and wood pulp harvested from eucalyptus tree farms.

Where Does SeaCell Come From?

Seaweed is harvested from the cool blue waters of Iceland every 4 years. Similar to how yaks graze, we only take the tops of the plant, leaving the lower sections to regenerate.

The wood pulp comes from Eucalyptus and Beech Trees, two fast-growing trees that require little water.

These trees are harvested in Europe from Forest Stewardship Council (FSC) certified tree farms. The FSC certification means that a newly planted tree must replace every tree used in the production of SeaCell.

The resulting combination is a durable, silky, breathable fiber that’s gentle on sensitive skin… After all, seaweed is choc-full of antioxidants, vitamins, amino acids, and minerals.

Wood Pulp, Lyocell Explained

You’re thinking, what the heck! You said seaweed; now I’m to understand that’s there’s wood pulp in here? So what is it, seaweed or wood? The short answer is it’s both.

We call it SeaCell and not WoodCell because the fiber's magic comes from seaweed. It’s the secret ingredient for summer sweaters. While theoretically, we could make a Lyocell fiber using 100% seaweed, it’s not practical or as environmentally friendly.

The two materials, seaweed and wood, are better when they work together.

Wood is denser than seaweed, which means that a bit of wood goes a long way, so we can use fewer resources to make more sweaters. Seaweed fibers are famously lush, skin-friendly, and lightweight, perfect for a summer sweater.

Additionally, seaweed grows abundantly without needing fresh water or arable land. By blending seaweed into wood-based lyocell, we've made a sustainable fiber even more Earth-friendly.

These two fibers are Simon and Garfunkle. Individually they are good, but when they work together, they have a profound gift of harmony.

Is Lyocell Eco-Friendly?

In making SeaCell, we use a combination of eucalyptus and beech wood certified by the Forest Stewardship Council (FSC).

We use these two species because they are sustainable hardwoods that grow abundantly worldwide in many different climates. They also grow on land that otherwise wouldn't be used for food production.

These trees also require a minimal amount of water compared to other plants.

Eucalyptus, in particular, is remarkably water-efficient, requiring 1/10 of the water of the average tree to grow.

Also, eucalyptus is fast-growing, making it a highly regenerative resource and one of the most sustainable materials in the yarn world. The fiber yield per acre from eucalyptus is 10x higher than cotton.

How Is SeaCell Made?

Let’s dig into how we get from seaweed and wood to a fiber ideal for our lightweight summer sweaters.

The first step is turning wood into fiber using a process known as NMMO or closed-loop technology.

Then, within the closed-loop, we create SeaCell while reusing the solvents. The NMMO transforms the wood into a liquid pulp.

To make SeaCell, ground seaweed is blended like a cake batter. Then, we take this "batter" and force it through tiny holes called spinnerets to create long thin fibers that we spin into yarns.

Fun fact: a spinneret machine is a mechanical copy of a spider's silk-spinning organ.

How Is The Seaweed Harvested?

The seaweed used to make SeaCell is technically an algae called Ascophyllum Nodossum, also known as Knotted Wrack, a strain of seaweed found in the Icelandic fjords and northern Atlantic.

Harvesting in the Icelandic fjords means there is no pollution and waste from ship traffic, so the seaweed is extremely clean and without pollutants.

Local Icelandic sea farmers gently harvest the abundant seaweed beds once every 4 years using large floating conveyor belts that remove the tops of the plants.

The harvesting process ensures that each bed can naturally regenerate without disrupting the ecosystem. Solely trimming the upper portion of the marine plant also encourages healthy growth, like cutting the split ends of our hair.

Once cut in Iceland, it’s transported to manufacturing facilities in Austria. The seaweed is entirely untreated, retaining all its natural properties.

What Are SeaCell's Properties/Benefits

We only use high utility sustainable materials. While khullu is the undefeated champ of wools, SeaCell is the best plant-based material. 

• Anti-Irritant: SeaCell fibers are smooth, unlike wool and cotton. The silky fibers don't irritate sensitive skin. SeaCell is efficient at moving sweat and moisture away from your body, discouraging bacteria growth that causes skin irritation.
• Breathability: Seaweed aside, Lyocell fiber also has some remarkable properties that make it perfect for a summer sweater. For example, compared to cotton, Lyocell is 50% more breathable. 
• Moisture-Wicking: SeaCell fibers retain 85% of their dry tenacity in wet conditions... this means that SeaCell moves moisture away from your body and into the air keeping you cool in the heat.
• Protection: The fibers effectively catch free radicals, which we are exposed to daily and can damage our skin cells. It’s hard to find a more soothing material to wear directly on your skin than SeaCell. The natural minerals in seaweed also protect against the sun with rating of up to UPF +50.
• Durability: SeaCell is durable; even the most durable synthetic fibers are only 20% stronger than SeaCell. SeaCell is also 2x stronger than cotton and viscose while dry and 3x stronger while wet. Being strong while wet exhibits how you can machine wash it many times over the years while retaining the shape of your go-to sweater. 

How Sustainable Is SeaCell?

Even sustainable brands, like Patagonia, can’t break their addiction to plastic-based synthetic fibers. Companies are tempted to make clothes from synthetic fibers because they are soft, strong, and globally abundant.

But plastic-based synthetic fibers are massive polluters through their manufacturing and leaching non-biodegradable microplastics into the world.

We can replace plastic-based synthetic fibers with SeaCell! It’s soft, abundant, and strong. However, unlike plastic polyester, SeaCell is made from regenerative resources and 100% biodegradable.

Seaweed grows abundantly in its natural saltwater ocean habitat. Eucalyptus proliferates without irrigation or pesticides and can be grown on extremely dry land. Both ingredients, seaweed and eucalyptus, use renewable energy in their production processes, and neither raw material needs additional fresh water to grow.

The Lyocell production process used to make Seacell conserves 99.5% of all waste and water in a closed-loop system that doesn’t leak toxic chemicals into the environment or require additional fresh water.

Why SeaCell Is Perfect For Summer Sweaters

It should be pretty obvious by now as to why we decided to use SeaCell in our summer sweaters. But, just in case, let’s go through and check the boxes, starting with the most important…

• Is SeaCell Sustainable? YES! It’s hugely sustainable every step of the way, from the collection of the raw materials to manufacturing fibers; SeaCell is arguable the world’s most sustainable yarn.
• Is SeaCell Breathable? SeaCell is naturally moisture-wicking, keeping you cool on even the hottest summer days.
• Is SeaCell Irritating On Skin? No! In fact, you can probably skip the spa after wearing a SeaCell summer sweater because the natural vitamins and minerals of the seaweed will soothe and protect you from harmful free radicals and damaging UV rays.

Additionally, our new summer sweaters are 3D-knit using an extremely fine gauge, meaning they are light as a feather.