When examining the effect of the substrate on the interface orientation, a slight dependence of the scaling of orientation with free energy difference is observed, with the observed orientation at the silicon substrate generally being shifted towards side-on relative to systems at the graphene-structured substrate (with either regular or strong interactions) for the same free energy difference (ESI Fig. ). As described previously in the context of the purely repulsive systems, this slight substrate dependence is likely due to the looser packing of substrate particles in the silicon substrate compared with the graphene substrate. This increases the dependence of the fluid-substrate potential on the in-plane coordinates of the fluid particle at the silicon substrate, which behaves as a slighly penetrable surface, relative to the graphene substrate, 6 Orientational order parameter s sub at the solid interface as a function of (a) overall, (b) energetic, and (c) entropic components of the interfacial free energy dierence. A least-squares best t to a logistic function, constrained to go to -0.5 and 1 at high and low ∆ Ū -T ∆ S respectively, is shown in (a). The energetic component is coloured by the interaction anisotropy parameter, the entropy component by the shape anisotropy parameter, and the overall free energy by the ratio of the two parameters. Filled symbols correspond to the graphene-structure substrate (graphene or "strong") and unlled symbols to the silicon substrate. Shaded grey regions highlight where the points should fall if obeying the predicted scaling with the free energy or free energy component.