Images that are composed exclusively of shades and tints of grey, scaling from black at the darkest to white at the brightest. Also known as black and white. If the image consists exclusively of solid black and white with no grey shading in between then it is also high contrast.
It is very common for comic and doujinshi to be in greyscale.
Using color tags like black eyes or black hair is discouraged when tagging greyscale images.
