Curve a in Fig. 4 illustrates a characteristic tear commonly called “knotty tear”. The word “knotty” designates a large magnitude transient increase in tearing force followed by a precipitous decrease. With this type of tear, the increase decrease process repeats in a cyclic fashion. Each increasing force stage eventually produces a rapid tear rupture which relieves concentrated stress and increases torn length. Just as the maximum force reached before tearing is a measure of tear strength, the level to which the force decreases before tear pauses also indicates important compound tear properties.