1.1 ,This test method covers the laboratory determination of the mass per unit area of a sample of a geosynthetic clay liner (GCL). The test method is also applicable to a multicomponent GCL. The dry mass of the clay can be found by simply subtracting the manufacturer's reported nominal mass of the geosynthetic component(s) from the total mass of the dry GCL. The moisture content of the GCL can also be determined by subtracting the initial total mass of the GCL from the total mass of the dry GCL.