Fig. 4. Silking force and tensile properties of fibres retrieved from a forced silking process characterized by high and variable silking force. (A) Silking force vs position along the silk fibre obtained from a silking process at 1 mm s^–1 reeling speed. The numbered intervals identify the samples shown in B and C. (B) Force–displacement curves of the silk samples obtained in the forced silking process shown in A. Base length=20 mm. For A and B, nominal reeling/test conditions were T=20°C, relative humidity=40%. (C) Stress–strain curves obtained by re-scaling the force–displacement curves in B using the individual cross-section of each sample. In B and C, samples are identified by a number, indicating the reeling interval in which they were spun, as labelled in A. NS, naturally spun fibres; FS, forcibly silked fibres; MS, maximum supercontracted fibres.