We placed the samples 300 mm from the 12keV incident beam and exposed them to X-rays for 10–60 min depending on the pre-measured signal intensity. Beam size was confined by a collimator 0.5 mm in diameter. Scattered radiation was detected by a Mar 345 imaging plate and two dimensional diffraction images generated for each silk sample using the program Fit2D (ESRF, Grenoble, France). From the diffraction images we calculated the diffraction angle (θ), intensity peaks (Ix), and 2θ full width and half width maximum intensities (FWHM) of the (200) and (120) diffraction peaks and the so called amorphous halo.