Elastic stretching, the one that reverses completely on taking the load off, is the regime where there is a linear relationship between the stress load and the

Elastic stretching, the one that reverses completely on taking the load off, is the regime where there is a linear relationship between the stress load and the stretching. This should be seen as different from yielding which in mechanical testing is an irreversible change usually signifying a destructive change in the material. So, yes, silk stretches but is not damaged while doing so and the resistance it provides at the time relates to its strength.