Black and Grey tattoos heavily draw on shading and the style is often used to create a 3-D effect without using colour. Highlights can be added using white ink, which smooths out sharp transitions between the different shades.
Black and Grey Background
The style known as black and grey is also known as "jailhouse" or "joint style,” having originated in prisons where inmates had limited access to materials, resorting to using guitar strings for needles and used cigarette ashes or pen ink to produce tattoos.
Tattoo studios popularised the style in the late 70s and early 80s, renaming it black and grey.