Action Comics, Vol. 1 # 844 and Batman, Vol. 1 # 655 had Variant Covers drawn by both of the Kubert Brothers. Adam and Andy Kubert going exclusive for DC Comics was big news back in 2006. Adam was gonna draw Superman, with a Script by Richard Donner and Geoff Johns. And Andy started his tenure on Batman, with a Script by Grant Morrison. To celebrate, the brothers did variant covers for each other’s books.
Andy’s variant cover for Action Comics was Inked by Jesse Delperdang, and Colored by Moose Baumann.
Adam was working in mixed media a lot around that time, and he did all of the Action Comics covers for his run in this same style, on that same sepia/brownish butcher paper. All of his Superman covers were published as-is too - just mixed media on brown paper. Pretty stuff. His Batman variant is one of my favorite images he’s ever created.