B.A.C.K. is the fourth studio album by the Danish thrash metal band Artillery. It was released in 1999 on Die Hard music, and their first full-length studio album since By Inheritance, which came out nine years earlier. After the release of this album, Artillery would break up again, but eventually reformed for a second time in 2007.

The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. It is the surface opposite to the chest, its height being defined by the vertebral column (commonly referred to as the spine or backbone) and its breadth being supported by the ribcage and shoulders. The spinal canal runs through the spine and provides nerves to the rest of the body.