Vanta black or Vertically aligned nanotube array black is the darkest material ever created. Vanta black is made of carbon nanotubes that capture almost all light that hits it preventing our eye from seeing any light that could bounce off of it. It is so dark that the human eye is unable to identify the depth of whatever is covered in Vanta black.
Both of these pictures are of the same thing just from different angles. The Vanta black is what prevents you from seeing anything when facing the front of the picture.