The formation of silk fibres in both spiders and silkworms is characterized by a conversion of short range ordered structures in solution into long range ordered beta-sheet rich structures in the final fibre. For silk we hypothesise that local flexibility of the protein chain will mediate silk protein storage/beta-sheet aggregation. To understand the mechanism we propose to study how concentration affects the local flexibility of silk fibroin both in its reactive (native) state and in a un-natural reconstituted silk fibroin. The results will have an impact on how we control silk storage and stability as well as for other hydrogen bonding polymers and proteins