Criteria for determining when a substance has this property are often mapped by separating hydrostatic and deviatoric components via projection onto the pi plane. Drucker’s postulate is a sufficient condition for the stability of materials with this property. EPFM theory must be used when a zone with this property around cracks is large. The Frank-Read mechanism leads to the creation of dislocations in materials with this property, increasing the material’s (*) toughness. A material has this property when a certain vector lies outside a cylinder by the von Mises criterion. Work hardening is used to strengthen materials with this property, the onset of which is given by the yield point and sees materials undergo necking. For 10 points, (10[1])name this solid property where an applied force causes a permanent shape (10[1])change, in contrast to elasticity. ■END■ (10[1])