Carbon nanotubes, essentially sheets of carbon atoms rolled into microscopic tubes, are exceptional light absorbers. The problem is that they are notoriously difficult to keep evenly distributed in a liquid coating mixture; they tend to clump, separate, and settle over time. To solve this, the team used a high-energy milling process to grind the carbon black and carbon nanotubes together in water along with dispersing agents. An accelerated stability test put the mixture through centrifuge forces more than 2,000 times the pull of gravity over seven hours, with only minimal separation, a strong indicator of shelf-stable industrial viability. Because carbon...