The degree with which wood shrinks and swells with changing moisture content is an important property which determines its suitability for different applications. This property, known as dimensional stability. Dimensional stability tests can be classified according to the method used to change the moisture content of the wood (liquid water or water vapor) and the duration of the test (until equilibrium is reached, or a shorter duration). Each class of test represents a situation that wood products may encounter in service, and different types of wood (modified or otherwise) may respond differently to each situation.