The use of bricks for constructing buildings began in the late 12th century. The main products from the medieval brickyards were so-called “cloister format” bricks, which were decidedly bigger than modern bricks, and semi-cylindrical mission or barrel tiles for roofing. Dogs’ paw prints, complete with pads and claws, but also prints from cats and martens are frequently found on bricks. The animals ran across the bricks before they were hardened, thus leaving their “fingerprints”.