Resiliency, as it applies to the wool fiber, means in practical terms that the material does not wrinkle readily; actually, it means that it won't stay wrinkled long. Simply hang a piece of wrinkled, rumpled, folded or creased woolen fabric over a support for a time and all but the most stubborn of wrinkles will vanish.
That points up the difference between elasticity and resilience, by the way. Elasticity refers to immediate recovery from deformation. Resilience (also a recovery from deformation) requires time. In textile use, elasticity generally means recovery from tensile leads, or stretching a yarn. Resilience usually means recovery from compression loads, or what happens when you stuff your sweater into a lunchbox. Flax notoriously lacks resilience. Linen fabrics wrinkle really, and the wrinkles stay until you approach them with something hot and heavy, like an iron.
Silk is neither as elastic nor as resilient as wool. However, no other natural fiber matches silk's combination of tensile strength, elasticity, and resilience. Silk is so extensible that this quality can be troublesome, because silk will stretch more than it will recover, and it stretches without great strain.
(Footnote) We seem to be edging into the realm of Fiber Science. What we are talking about now is called recovery. A yarn or fiber is stretched some nominal amount, say 3 percent of its length; it is then allowed to relax, and the length again is measured. With 100-percent recovery, the length is exactly the same as before stretching. At 3 percent elongation, silk has a recovery figure of about 90 percent, wool about 97 percent, cotton about 70 percent, and flax is down about 60 percent. But before you think that these figures are terribly significant, consider the forces involved. The load required to elongate a linen yarn 3 percent is about 1½ times greater than an equivalent silk yarn can survive. In fact, that load will stretch the silk yarn about 25 percent and then break it. The same load is about five times greater than the load required to break wool, after stretching it 40 percent. The same load will stretch cotton about 6 percent, and just barely break it. The bottom line? Cotton and flax don't stretch.
Extract with footnote from The Alden Amos Big Book of Handspinning page 122.











