Vantablack's major claim to fame is that it absorbs all but 0.035 percent of light. How? By using carbon nanofibers so small—10,000-times thinner than a strand of hair—that light rays can barely penetrate it.
Aside from being just generally cool looking, this stuff can play tricks on your eyes. That's wrinkled tin foil underneath; it's blocking so much light that the surface underneath looks totally flat.