This method has enabled us to quantify the dependence of living CDSA kinetics on unimer concentration, seed concentration, and selective solubility. Living CDSA shares obvious similarities with living covalent polymerization, where unimer and exposed active sites at the platelet edges are analogous to the monomer and initiator in the reaction. Here, 2D platelet formation of PCL 45 :PCL 45 -b-PDMA 348 was well described by a kinetic model based on such assembly at the living edge of the forming platelet, with a sub-unitary overall order of reaction and dependence of growth kinetics on the nature of the block copolymer. This deviation from simple first-order kinetics has been previously attributed to conformational dispersity of the block copolymer. This is particularly intriguing when considering the variation in contrast within growth annuli in our examination of the growth of multi-annulus platelets (Fig. ). Secondly, observed variations in contrast across individual annuli are of note (Fig. ). One interpretation could be a change in composition, perhaps caused by a variation in the relative rates of deposition of PCL 45 and PCL 45 -b-PDMA 348 . These observations warrant further investigation, mapping how different building units might assemble differently as 2D platelet shape evolves.