Spider silks are known to have outstanding mechanical properties yet there is still much unknown about how the initial structure, storage and transformation of the silk proteins influence these properties. We have recently characterised the intial shape and size of native silkworm and four principal spider silk proteins in solution, using small angle scattering. In addition to flow, it is known that the concentration of metal ions and pH varies as the silk proteins are processed by the silkworm or spider to form the silk fibre. We wish to examine how these chemical changes influence the size, shape and flexibility of native silk proteins in solution. By comparing silkworm silk with the 4 principal spider silk proteins we will show whether all the silks may have a similar processing route and thus will be directly relevant to our understanding of these high performance natural fibres.