VANTABLACK—THE NEW “BLACKEST BLACK”. Vantablack is, according to this wikipedia entry, “the darkest artificial substance…known, absorbing up to 99.965% of radiation in the visible spectrum.” According to this wikipedia entry, “color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object’s physical properties such as light absorption, emission spectra, etc.”
Vantablack, by absorbing almost all reflected radiation, is blacker than anything yet found. It is a chemical substance made of vertically aligned carbon nanotube arrays. The name comes from the initial letters of “Vertically Aligned NanoTube Arrays”.
When light strikes Vantablack, instead of bouncing off from it, it becomes trapped and is continually deflected amongst the tubes, eventually becoming absorbed and dissipating into heat.
It was discovered in 2014 and its original intended purpose was for use in satellite-borne blackbody calibration systems, whatever they are.