Interesting residue from the process of creation (or, I suppose, manufacture—the two kind of blend in printing). Here's the photographer's caption: "This is in the basement of the building I work in. We used to have a gigantic press there. This is part of what remains." It seems like they didn't use (or at least smear) as much magenta as yellow, cyan, and (of course) black. I wonder if that's standard for print projects?