As will be discussed later, however, the change in scaling at ~10 mg/mL is likely due to fibril interactions as opposed to polymer interactions due to the concentration dependence of retardance occurring at timescales too slow for individual polymer relaxation. The retardance profiles for shear and extension were measured for concentrations ranging from 2 to 10 mg/mL in both CB and CB/DMF solutions. The retardance profiles for each concentration are shown in supplementary Figure . To compare the relative degree of alignment across different concentrations, we normalize the retardance by concentration to get the specific retardance . This value is proportional to the specific birefringence as well as the birefringence normalized by the birefringence at full extension since which has been used to characterize a polymer's degree of extension . For shear flow, the specific retardance of PII-2T in CB and CB/DMF is shown in Figure and B, respectively.