Tear Strength may be measured by using an Instron® tensile tester or an Elmendorf tear tester. For the Instron® test or trouser tear method, samples are cut to a precise rectangular shape with a notch, resembling a pair of trousers. The two "legs" are fastened in the grips of the Instron® tester and pulled, thereby measuring and recording the force required to tear the sample. For the Elmendorf tear test, a sample is cut to a precise shape and notched. It is fixed into the machine and torn using a pendulum arm. The force required to tear the sample is measured and recorded.The Packaging Technology Center of Cardinal Health offers tear strength testing.