Starting with the example of Figure (found in the top right corner of Figure ), one can see that the absolute maximum size that can be achieved is found at low overall flow rates and high THF mixing ratios. The drop off, as discussed above, only occurs at high flow rates. Generally, it is quite straight forward to determine optimum conditions for synthesis of particles of a specific size from this plot. Further, one can take economic factors into account, as for a specific size a range of conditions would be successful. It may be advantageous to choose high flow rates (which translates to high space-time-yields), while low THF content may be advisable as the organic solvent often needs to be removed after synthesis depending on the application. As an example, for PEMA75-PDMAEA50 at 10mg/mL it may be best to synthesize a particle of 100nm at around 6 ml/min flow rate and a 20% THF ratio. Further analysis of Figure (a) reveals that the polymer concentration has a very substantial effect on the outcome of the experiment. While the overall shape of the 3D surface may be on first glance not too dissimilar, particle sizes are considerably larger already, even if the polymer concentration in THF is only reduced to 7.5 mg/ml. Even more interesting, when further reducing the concentration (upper left plot), the absolute size regime is reduced again, yet suddenly the mixing ratio has a much lower impact on the obtainable size. All in all, this shows how complex the dependencies in these systems are, and that it is difficult to generalize results. With all systems and conditions tested within this study, the only thing we can say is that low total rates tend to yield larger particle sizes, at least in most cases (notably, PS90-PPEGMEA23 at 2mg/ml yields the largest particles at the highest flow rate, see supporting information). What can be generalized though is that with this data it becomes clear why nanoparticle synthesis from batch procedures often suffers from very low reproducibility. Batch procedures allow for much lower control over individual synthesis parameters, and hence data obtained from batch can appear erratic. With the flow system in combination with the described automation, it may become for the first time possible to map the influence of synthesis parameters accurately.