Scientists have created the darkest known material:

Pulickel Ajayan, a professor of engineering at Rice University, created a carpet of carbon nanotubes that reflects 0.045 percent light, making it 100 times darker than a black-painted Corvette, the Houston Chronicle reported Monday.

...The previous darkest known material, a nickel and phosphorus alloy created by scientists in London, reflected about 0.16 percent of light.