Rayon yarns grafted with poly(ethyl acrylate) become highly elastic following decrystallization in aqueous zinc chloride solutions. An increase in temperature speeds up the decrystallization rate but does not have a substantial effect on the ultimate elongation properties of the grafted fiber. Increasing the concentration of zinc chloride does not have a marked change in the extension properties of the grafted fiber until 70% zinc chloride. At this saturated concentration, there is a sudden and dramatic change in the elastic properties of the grafted fiber. In fact, the grafted fibers after decrystallization in 70% zinc chloride have elongations in excess of 800%.