Consequently, the intensity within our q-range window actually decreases, although it increases at even lower q-values outside our range. Considering that the intensity in Eq. 3 depends on the radius, electron density contrast, and volume fraction, it is practically impossible to discriminate among these contributions in our experiments just by considering a single curve without a context of the entire time series. Since we do not know ϕ or Δρ a priori, which may also evolve during the precipitation processes, we cannot determine the particle radii directly. However, since our data are time-resolved, and it is logical to assume that crystals grow from small to large sizes, the decrease of Porod intensity at 300 s (Fig. ) is explained by the growth of crystals towards larger sizes. Furthermore, by definition I 0 is proportional to a specific surface area. Thus, for a constant electron density contrast, its evolution in Fig. should follow a I 0 ~1/radius dependence for growing particles, which is indeed the case. This would be rationalised by the scenario in which no new crystals are nucleating, and instead the already existing ones grow (see Fig. ), Fig. . Building on this explanation, we now investigate why no amorphous particles are directly observed in the scattering patterns, despite their radii of ~20 -25 nm (cryo-TEM, Fig. ) being well within our q-range. In this regard, we did not observe any obvious form-factor-like features for q > ~1 nm -1 in Fig. that could be attributed to such particles.