Model material is a term used to describe the materials used to create models, such as for architectural or engineering purposes. The three most common model materials are KIT, BALSA, and CLAY. KIT stands for 'Kitset', which is a type of pre-made model that can be assembled with minimal effort. BALSA is a lightweight wood that is often used in model airplanes and other small scale models. CLAY is a malleable material that is used to create detailed models, such as sculptures.