Stretching (sometimes erroneously referre to as gauging or scalpelling), in the context of body piercing, is the deliberate expansion of a healed fistula (hole in the skin) for the purpose of wearing body piercing jewelry. Ear piercings are the most commonly stretched piercings, with nasal septum piercings, tongue piercings, industrial piercings and lip piercings/lip plates following close behind. All piercings can be stretched to some degree, however. Cartilage piercings are usually more difficult to stretch, and more likely to form hypertrophic scars or keloids if stretched quickly. Healing is very important in between stages of stretching.