The effect of spinning conditions on the mechanics of a spider's dragline silk

We studied the mechanical properties of dragline threads of the edible gold en silk spider Nephila edulis that are produced under spinning speeds rangi ng front 0.1 to 400 mm s(-1) and temperatures ranging from 5 to 40 degreesC . These conditions affected the silk in all of the mechanical traits we tes ted (strain at breaking, breaking energy, initial Young's modulus and point of yielding). We argue that both trade-offs (between mechanical properties ) and constraints (in the manufacturing process) have a large role in defin ing spider silk fibres.