What is 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.

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.

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.

Our algae starts life 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 dye.

Built with carbon capture technology

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. Once the t shirt has been built and dyed, the black algae dye 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 t shirt you’re wearing is storing carbon emissions. This is known as carbon capture technology and it means that rather than producing emissions, the Black Algae T Shirt does the exact opposite.

Made with seaweed from Icelandic fjords

As well as using algae to reinvent colour, we’re also exploring how it can be incorporated into fabrics. One fifth of the t shirt’s base fabric is pulped eucalyptus that’s blended with brown algae, a type of seaweed known as ‘Knotted Wrack.’ The eucalyptus is sourced from sustainably managed forests, while the brown algae is harvested from Iceland’s North Atlantic fjords where it grows in abundance. By only cutting off the top parts of the seaweed we leave the rest to quickly regenerate and regrow.

Combined with organic cotton

The other 80% of the t shirt is made from soft organic cotton that’s grown using natural solutions in place of artificial fertilisers and toxic chemicals. This helps to maintain soil health, conserve water and promote biodiversity. We chose this combination of cotton, eucalyptus and seaweed because the fibres absorbed the dye best out of all the materials we trialled.

Garment dyed and emerized for softness

While most clothes are dyed with a process called piece dyeing – where huge rolls of fabric are dyed, before being cut and sewn to make clothing – we garment dye every Black Algae T Shirt by fully submerging it in dye to give it its colour. The t shirt is then emerized – a mechanical process where it essentially gets sandpapered by an abrasive material to make the t shirt phenomenally soft.

Even the labels are printed with black algae ink

Every detail of the t shirt is made with materials from nature. The stitching is 100% cotton thread. And even the size label and care label are printed with black algae ink that’s made from the same algae waste as the dye.