Many works of art are very sensitive to air that is too dry or too humid. Works of art often contain natural materials such as wood, paper or linen. If the ambient air is too dry, these materials release moisture into the ambient air. As a result, the materials become drier, shrink, warp and can tear. As a work of art ages, it also becomes more fragile and less stretchy and it becomes increasingly difficult to keep it in optimal condition. With the right humidity, visitors can continue to enjoy the works of art for years to come.