The worlds ‘blackest black’ paint is now available to purchase! The special acrylic paint is formulated to absorb between 98% and 99% of light and its safe to say that the end result is nothing short of amazing!
To start, Semple and his team “went back to the basics of paint making.” They knew that the issue with existing black pigments was that they have some sheen to them. To avoid the shine, they created their own pigment called Black Magick. Because it was “born matte,” they didn’t have to add the slightly grey tinters found in Black 2.0. Semple also formulated a new acrylic polymer to bind the pigment. “It’s special because it has more available bonds than any other acrylic polymer being used in paints,” he explains. “This means it can cling onto way more pigment, leading to a really dense pigment load and a depth of colour not previously possible.”
Image Credit: Culture Hustle
That said, there are off the shelf paints already that push 98% absorption, so I don't know if this is that much darker than what is on the market. There are plenty of applications where paints aren't so good too, as it depends on the chemicals used in the binders and things like temperature range, mechanical strength, how much power it can absorb, etc. At my job I am often stuck using just graphite for as an optically black material, which isn't that dark but meets all of the other requirements.
https://www.surreynanosystems.com/super-black-coatings/vantablack-s-vis