Tear strength (Elmendorf)
Also: Elmendorf tear, tear strength, tearing resistance
The force required to propagate a tear in paper, measured by Elmendorf pendulum tester in mN.
Elmendorf tear strength measures the force needed to tear a paper sample that already has an initial slit. A pendulum drops and completes the tear; the energy absorbed is converted to force. The test is defined by ISO 1974.
Tear strength depends heavily on fiber length. Long softwood fibers give high tear (which is why kraftliner outperforms testliner). Tear strength matters in sack kraft (tear-resistance during handling) and in printing papers (running on fast presses without tearing).