“…Whilst there have been several concerted modelling efforts to relate silk’s structures to its mechanical properties [ 3 , 4 , 5 , 6 , 7 , 8 , 18 , 19 ], accounting for the precise contributions of each of these structural elements on a fibre’s mechanical response has been inconclusive. Consider, e.g., the role played by the interfaces between the fibrils, which some studies define as mechanically weak and responsible for easy slippage of adjacent fibrils [ 6 ], while other studies observe the presence of heterogeneous protrusions along such surfaces determining a non-slip kinematics and energy dissipation due to interlocking effects [ 20 ]. In addition, while the literature to-date is populated by a number of multiscale and hierarchical approaches to the mechanics of the dragline silk [ 1 , 2 , 3 , 4 , 5 , 6 , 18 ], and there is experimental evidence of the partitioning of the spider silk fibres into layers with different mechanical behaviours [ 7 , 8 ], one observes that the grading of the mechanical properties along the radial coordinate of silk fibres has not been extensively investigated.…”