Typically, crushed stone or gravel is used as a base material under artificial turf. The purpose of the base material is to create a stable and level surface for the turf to be installed on.

The base layer helps to support the weight of the artificial turf and provides a solid foundation for it to sit on. It also helps to prevent the turf from shifting or settling over time, which can create an uneven surface and damage the turf.

Crushed stone or gravel is a good choice for a base material because it provides excellent drainage and allows water to pass through quickly. This helps to prevent water from accumulating on the surface of the turf, which can cause mold and other issues. Additionally, crushed stone or gravel is durable and long-lasting, so it can provide a stable base for the artificial turf for many years.