Prison tattoos are notorious for being crude, simple drawings, done with items you generally don't want in your skin. Paper clips, razor blades, shards of glass, and wires are used with charcoal, burned rubber, pen ink, and pencil lead - basically whatever a prisoner can get his hands on behind bars. But what makes these tattoos unique is that they have been cut off the bodies of dead inmates.
These tattoos belonged to Polish prisoners. After they died, the skin containing the art would be cut away and sealed in jars of formaldehyde. Artist Katarzyna Mirczak found these stacks of samples at the Jagiellonian University in Krakow and began photographing them. The tattoos were collected to study social cues and "alternative culture," but frankly, I can't get past the fact that these are cut up chunks of human flesh. You can see hair sprouting out of some of the chunks; other skin slices still have nipples attached.