London-based material design studio The Unseen has a way of infusing products with a bit of magic–from its witchy color-changing hair dye to hypercolor fashion pieces. The studio’s latest release is more down to earth, though no less enchanting: cabbage-dyed T-shirts that change color in the wash, based on your city’s water pollution.
That means the T-shirts, made in collaboration with British lifestyle company The Lost Explorer, will come out of the washing machine differently in London than they will in New York or Buenos Aires. The shirts start out a deep purple, thanks to a homemade cabbage juice dye. But as you may recall from elementary school science class, cabbage is also a natural pH indicator. It will turn red, pink, or magenta in acids and blue, green, and yellow in alkaline solutions.
Meanwhile, the pH level of water is also an indicator of how much it is polluted. Emissions from mining and smelting operations or fossil fuel combustion can make water become more basic. Wastewater discharge that contains detergents and soap-based products does the same thing. In general, a water source’s pH fluctuations is typically related to pollution in the air, soil, or directly into the water.
Lauren Bowker, the founder of The Unseen, and David de Rothschild, founder of The Lost Explorer, decided to adapt this natural pH indicator to garments. The color-changing T-shirts they created are part of a campaign in conjunction with World Environment Day to raise awareness of climate change. While the T-shirts are not available for purchase, the pair made a how-to video with step-by-step instructions for how to make your own.