Engineers at Purdue University in Indiana USA have developed an ultra-white paint incorporating barium sulphate particles that is up to 98.1% reflective. This compares to a reflectivity of 80–90% for other white paints designed to reflect sunlight that are currently available. Such paints are considered to be a potential game ganger for keeping the planet particularly cities cooler and reducing electricity use and buildings with a coating of this would need to rely far less on energy hungry air conditioning