Geosynthetic clay liners （GCL） is a geocomposite consisting of a layer of bentonite encapsulated between two Geotextile non-woven needle punched geotextiles. The three layers are then needle punched together for maximum performance under a wide variety of field conditions.

This integrated matrix of bentonite and needle punched fibres provides high shear strength and allows the GCL to offer low permeability even when installed in adverse conditions.  GCL has high internal shear strength characteristics for steep slope applications.