Fig. 2.

Geometric and rheological considerations. a Previous geometric approximations of silk ducts showing the variation in radius as a function of distance along the duct. Curves represent Asakura (orange dashes) and Breslauer’s (blue line) hyperbolic approximations, along with the linear model employed by Kojic (green dots). The equations describing each curve can be found in Supplementary Table 1. b – Exemplar rheological response of silk feedstock to increasing shear rate, showing four distinct regimes - (1) – Pseudo-Newtonian behaviour at low shear rates; (2) – Shear thinning behaviour; (3) – Fibrillation, increasingly elastic response; (4) – Viscoelastic solid, second plateau reached