The demand for models is projected to grow, as turnover is high and new models will be needed to replace those who retire. Formal education or other credentials are not required to begin a modeling career, although attending classes can help candidates develop desired skills such as makeup artistry and posing. Many clients prefer a certain height, age and weight, but opportunities for all body types are expanding as customers increasingly desire realistic representation. Prospective models should have a tolerance for long and unpredictable hours.