. As can be seen in Fig. (purple dashed line) the strong decay of the material strength transitions at a 0,min = 17 µm into a shallow decrease, meaning that rather independently of the initial crack length a 0 the strength of the composite is approximately 100 MPa which allows achieving high strength values in the same order of magnitude as their respective supercrystalline material systems, even though the specimen size is now increased by two orders of magnitude. This relative increase in fracture toughness is even more remarkable considering that the building blocks on each hierarchical level are spherical, and not anisotropic, brick shaped hard fillers such as those of nacre or nacre-like materials for which such toughening effects are expected. Furthermore, the question arises why the R-curve ends at ∆a max = 270 ± 40 µm. The answer is that for the 3-point-bending configuration and initial crack lengths of ∼ 0.3 mm the derivative of the compliance versus crack length (see the SI, Eq. 3) is stronger than the slope of the R-curve and hence unstable crack growth occurs. For a deeper understanding of the R-curve, the corresponding bridging stresses should be calculated. This would enable to model the fracture behaviour of the 2 HL composite more fundamentally, but goes beyond this investigation.