In the traditional butchering practice that prevailed until the late 20th century but is now rare, animal carcasses are divided at the slaughterhouse into large pieces—halves or quarters—which are then delivered to retail butchers, who break them down into roasts, steaks, chops, and the other standard cuts. The meat might not be wrapped at all until sale, and then only loosely in “butcher’s paper.” Such meat is continuously exposed to the air, so it tends to be fully oxygenated and red, and it slowly dries out, which concentrates its flavor at the same time that it leaves some surface areas discolored and off-flavored and in need of trimming.