The black that swallows 99.965% of light

Surrey NanoSystems unveiled in July 2014 a material so dark that the eye couldn't tell whether a coated object was flat or dented. They called it Vantablack —Vertically Aligned Nano Tube Arrays— and it was a forest of carbon tubes 14 to 50 microns tall: light entered between them and found no way out. It absorbs 99.965%. NASA tested it to paint the insides of telescopes and cut down stray light. In 2016, sculptor Anish Kapoor signed the exclusive artistic licence; no other artist could buy it. Stuart Semple, a British painter, hit back by releasing a fluorescent pink called Pink that he sold to anyone except Kapoor —you had to swear on the website you weren't him— and later a homemade black, Black 3.0. Kapoor posted a photo with the pink staining his middle finger. The factory version still costs tens of thousands of pounds per square metre and only bonds to anodised aluminium at 100 °C: try to scratch it and you lift the whole substrate.