Technical details
Open Accordion
Size + fit
Open Accordion

Fit guide: The Hemp and Black Algae Sweatpants are designed with a regular fit.

Model wears: Sadiq Desh is 6ft 1.5 / 187cm with a 32in / 81cm waist, and wears the Hemp and Black Algae Sweatpants in size Small.

Personalised advice: See our size guide for more advice on sizing, or you can ask us for personalised sizing advice here.

Returns and exchanges: Don’t worry if you order something and it doesn’t fit – we have a free, no hassle 30 day return and exchange period.

XSSMLXLXXL
Fits waist71-7676-8181-8686-9191-9696-101
Outside length9899.5101102.5104105.5
XSSMLXLXXL
Fits waist28-3030-3232-3434-3636-3838-40
Outside length38.539.139.740.340.941.5
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Hemp and Black Algae Sweatpants

Black algae and hemp are nature’s most futuristic materials

If scientists invented two new materials that could produce over half the oxygen in the world, and clean up soil and air after nuclear meltdowns – all whilst sucking up carbon dioxide – it would be hailed as a miracle. But algae and hemp both do it for free. And over the next decade they’re also going to reshape how clothing and colour itself are made. So as we continue on our journey of building clothing from the materials that will shape our planet’s future, algae and hemp are as high up the list as you can get. And it’s why our Hemp and Black Algae Sweatpants are made entirely out of them.

Hemp and Black Algae Sweatpants

Making clothes like our ancestors made them

While most industries can be improved by heading forwards as fast as possible, one of the biggest advances clothing can make is by heading backwards a few thousand years to when our ancestors were making clothes from grass, tree bark, animal skins and plants. Today we’re trying to get back to using nature to make clothes that require as little energy as possible and leave almost no trace of their existence at the end of their lives. And this means breaking apart many of the standard processes used in the industry today.

Hemp and Black Algae Sweatpants

What is carbon black

With the Hemp and Black Algae Sweatpants we’re going back to the very start of the supply chain to take on a harmful and pervasive pigment known as carbon black. Unless you’ve spent your life on a desert island with no clothes and no possessions, you’ll run into carbon black every day. It’s in the ink in your black pen, your black phone case, and the tyres on your car. Carbon black is the pigment that’s used to make black things black. But we don’t question where it comes from because very few people know it’s even there.

Hemp and Black Algae Sweatpants

Making the colour black hasn’t changed for 100 years

The way carbon black is made hasn’t really changed for over a century. At mass scale the process begins with a fossil fuel like heavy petroleum which is fed into an industrial furnace and allowed to partially combust. This creates a black powder that looks a bit like soot. And this is carbon black. It’s then used to colour everything from inks, to plastics, to rubber, and you’ll find it everywhere on the planet.

Hemp and Black Algae Sweatpants

Why we’re looking for alternatives to carbon black

There are lots of problems associated with carbon black. The manufacturing process creates greenhouse gases which are released into the atmosphere. And the heavy petroleum needed to make it comes from places known as oil sands, or tar sands. These are barren areas of our planet that are stripped of all vegetation so that oil can be extracted from the ground. And as ecosystems are eroded more carbon is emitted.

Hemp and Black Algae Sweatpants

We’re working with a US biomaterials startup

With the help of US biomaterials company Living Ink, we’ve found a method of making our Hemp and Black Algae Sweatpants without using any carbon black. After their founders Scott and Steve discovered that an algae cell is almost identical in size to a carbon black pigment, and can create the same colour, they’ve been on a mission to replace carbon black ink with a black ink made from black algae waste.

Our algae is grown in giant ponds

The algae we use starts life in huge open-air ponds where it grows by feeding on sunlight, carbon dioxide, water and nutrients. These ponds contain vast quantities of spirulina algae which absorb carbon dioxide and pump oxygen back out into the atmosphere. While the majority of the algae is used to make natural food colourings, the rest of the algae is harvested and used as the base for black algae ink.

Hemp and Black Algae Sweatpants

A thermo treatment turns the algae into ink

After it’s harvested, the algae by-product is heat treated to concentrate it into a black powder which we use as pigment. This treatment seals in carbon dioxide which has been absorbed by the algae during its lifespan, preventing it from making its way back into the atmosphere. The black powder is then purified and mixed with a water-based binder to create black algae ink.

Hemp and Black Algae Sweatpants

Printed with black algae ink

To make a normal pair of black sweatpants you dye the fibres black. But black algae dye hasn’t been invented yet. So we print the entire outer surface of the hoodie with black algae ink – turning the sweatpants a dark grey. The ink has been engineered to be UV resistant so it holds its colour for years. But as it’s bio-based and printed on hemp it won’t behave exactly like a petroleum-based ink. Over time the black colour will brighten around the edges next to the seams as it ages.

Hemp and Black Algae Sweatpants

Built with carbon capture technology

Once the sweatpants have been built and printed, the black algae ink continues to lock in the carbon dioxide that it absorbed when it was alive. And it will do this for over 100 years. So the sweatpants you’re wearing is storing carbon emissions. This is known as carbon capture technology and it means that rather than producing emissions, the Hemp and Black Algae Sweatpants do the exact opposite.

Hemp and Black Algae Sweatpants

We’ve combined black algae with hemp

The Black Algae Sweatpants are really a story about two different technologies. The first is obviously algae. The second is one of the most extraordinary plants on Earth – hemp. Over the last 80 years hemp has been one of the most misunderstood and badly treated materials on the planet. It’s been banned by governments, had war declared against it, and been accused of bringing down modern society. But its ancient past shows it could have a very different future.

Hemp and Black Algae Sweatpants

Hemp is incredibly strong

50,000 years ago early man understood the power of hemp and used it to spin the first ever fibre. With 4x the durability and 8x the tensile strength of cotton, the Egyptians then used it to haul rocks around when they were building the pyramids. The Vikings relied on hemp ropes, sails, and nets for their voyages. Chinese warlords built their armour from it. Christopher Columbus’s voyage to the New World in 1492 was made possible thanks to the strength of his hemp sails – in fact he was so concerned about getting stranded in whatever distant land they reached, he loaded his ships with hemp seeds in the case they needed to grow more sails.

Hemp and Black Algae Sweatpants

Seven US presidents smoked it

At one time, hemp was the solution to almost any problem. Leonardo da Vinci painted the Mona Lisa on hemp canvas – the word canvas comes from cannabis. Early presidential letters indicate that at least 7 presidents, including George Washington and Thomas Jefferson, smoked it. And one of Henry Ford’s most cutting-edge cars was almost entirely built out of hemp and ran on hemp fuel, leading Mechanical Engineering magazine to call hemp “the most profitable and desirable crop that can be grown”.

Hemp and Black Algae Sweatpants

Today hemp is a plant with a PR problem

But then things went sideways. The petrochemical, pulp-paper and nylon industries – who all stood to lose billions of dollars if the commercial potential of hemp was realised – campaigned against it. Propaganda, conspiracy theories and drug hysteria kicked in soon after, and hemp’s position as the wonder plant of the future took a beating with headlines like “Marihuana: The Assassin of Youth” and “Sex-Crazing Drug Menace.”

Hemp and Black Algae Sweatpants

War was declared on hemp

In 1937 Roosevelt passed the Marihuana Tax Act effectively making hemp pointless to grow because it was so expensive. And by the 1970s the DEA’s war on drugs was funding a program to crop dust fields of hemp with paraquat, a chemical herbicide known to cause irreversible kidney damage, respiratory failure, and death.

Hemp and Black Algae Sweatpants

Hemp is on a comeback

By the mid 80s the only two hemp products you could buy legally in the US were Hungarian twine and sterilised bird seed. But conservationists lobbied for its return, citing its huge economic and environmental benefits. The UK and Germany resumed commercial production in the 1990s. In 2013, farmers in Colorado harvested several acres of hemp, bringing the first hemp crop to the US in over 50 years. And today at least 47 US states have enacted legalisation to establish hemp production programs or allow for hemp research.

Hemp and Black Algae Sweatpants

Hemp is a high-performance material

With advances in man-made materials, and the myth and misconception that surrounds everything associated with cannabis, hemp’s unique properties could easily be forgotten. But they shouldn’t be. From an environmental perspective every tonne of hemp produced removes 1.6 tonnes of CO2 from the air. It kills weeds, purifies soil, grows super-fast and will thrive almost anywhere in the world. It requires zero pesticides and very little water to cultivate. And it’s so smart scientists now use it to clean up soil, water and air contaminated with radioactive isotopes after nuclear meltdowns.

Hemp and Black Algae Sweatpants

Our hemp is incredibly soft yet strong

As for clothing, a single hemp fibre can grow to over 4 metres which makes it incredibly soft yet really strong – as there are fewer joints to act as weak points. New developments in the way we process the fibres mean it can be used to create some of the most soothing natural fabrics around, but without compromising on strength and durability. Hemp keeps its shape and won’t go saggy. It resists pilling and softens over time, meaning it gets more comfortable the more you wear it. As the saying goes, “hemp doesn’t wear out, it wears in.” It’s also breathable, water repellent, antibacterial and UV resistant.

Hemp and Black Algae Sweatpants

Irrigated with mountain rainwater

We source our hemp from the most northerly province in China, Heilongjiang, working with a partner committed to producing materials sustainably. The region is known for its remote mountain ranges which supply farmlands with clean rainwater. They use this rainwater to irrigate the hemp fields, which reduces water consumption and leads to a stronger and smoother hemp plant. And that leads to stronger and smoother pair of sweatpants.

Hemp and Black Algae Sweatpants

What the sweatpants feel like

The Hemp and Black Algae Sweatpants are soft and easy to wear. The fabric’s fibres are hollow – just like you get with other natural fibres like Merino – so it traps pockets of air to keep you warmer in winter, but it also allows the hoodie to breathe easily in summer. We’ve blended our organic hemp with organic cotton grown in the same mountainous region to make it even softer. And it’s this mix that makes the sweatpants so comfortable. The underside of the material has a fleecy texture, and you’ll find two hand pockets which are super soft on the inside.

Hemp and Black Algae Sweatpants

Elasticated and rope tied waist

The sweatpants are elasticated at the waist and fasten with a rope finished with macramé, an ancient ‘square knotting’ technique dating back to Babylonian times. As part of the challenges of working with clothes made from nature, we’re still in R&D searching for solutions to the waistband and drawcords. For now, the waistband needs to contain a small amount of elastane to do its job, and the cords (which can be removed) are treated with dye, as we can't print rope with black algae yet.

Hemp and Black Algae Sweatpants

You can wear them all day long

Because hemp fibre is porous, it’s naturally highly breathable and moisture-wicking, so it’s easy to wear all day. It can absorb up to 20% of its own weight while still feeling dry. It’s also antibacterial, so if you want to smell good all day long, hemp is the perfect choice. It blocks UV-A and UV-B rays. And thanks to its high resistance to ultraviolet light, it won’t disintegrate from sunlight like other natural fabrics.

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