White foam boards can be obtained in various thickness but the most common thickness goes from 3-5 mm. These are solid boards can be utilized as a foundation for models that are built with foam or any such lightweight material. These can also be used for wall construction. Similarly, cork sheets are used where flexibility is needed and are much easier to handle. Foam sheets are flexible and less brittle than others. Other commonly used materials includes wood, papers, wires, clay, heavy Canson and so on. If you have patience you can also try paper mache or gypsum.