According to the Geosynthetic Institute, the “Multi-axial Tensile break” test is the best measure of ductility. This test measures a product's ability to elongate in all directions without breaking. Geo-Form EPDM Rubber Alloy Lining elongates or stretches in all directions with low force but it is not elastic. It does not recover or shrink back.  Multiple years of observations of Geo-Form EPDM Rubber Alloy Lining installations has shown this lining to “mold” to the shape of irregular canal subgrades and form around stones or other imperfections in the site preparation. It will also adjust to soil settling or movement over time.  "Ductility in a geomembrane liner is often a far more important parameter than strength." * * Dr. Ian D. Peggs, President of I-CORP INTERNATIONAL, Inc., USA, specializing in geosynthetic materials performance.