graphic designers Sam Cox and Justin LaRosa. They’ve teamed up as Physical Fiction to bring Lego to the letterpress. They use smooth tiles as pixels in their video-game-like designs, snapping them on a flat Lego base mounted to wood. Paint is applied with a roller, and the whole thing is pressed to paper, leaving their inked impression.
More about the Lego Letterpress and the artists behind it in this article on npr.