Generally, the filling material inside mahjong tiles is likely a substance with a certain weight and texture. For example, some mahjong tiles are filled with talcum powder, a common mineral powder that gives the tiles a certain weight in the hand and helps maintain their shape. Others may be filled with plastic-like particles, which can be used to adjust the weight and feel of the tiles as needed.
Additionally, there are also cases where specially formulated sand or other similar filling materials are used. Different filling materials affect the feel, weight, and sound of the tiles when used. Some high-end mahjong tiles may use higher-quality, finer filling materials to enhance the overall quality and user experience.
