Tearing is a common mode of failure for geotextile materials subjected to tensile stresses. Unlike other textile fabrics, geotextiles do not often fail in the ripping fashion simulated by the tongue or trouser tear test method, but experience tearing when under tensile plane stresses. This type of tearing is simulated by the trapezoidal tear test and is used to determine the force required to propagate a tear that has already been created in the material. The trapezoidal tear test clamps opposite sides of the fabric so that the non-clamped edges of the fabric forms a trapezoid with the grip faces. This set up is then pulled perpendicular to the tear line, with the force acting in the plane of the fabric.