“Apollian Gasket.” The idea that an infinite amount of circles can be made in the spaces between other circles.
Done 4/24/12 by Patrick at Tat2 Heaven, in Rockford, IL. While he was working on it, he kept making little jokes like “annnddddd another circle… What’s next? A circle,” but when he was completely done he ended with “you’re going to be so pissed, I did a bunch of squares instead!” :)