After solvent evaporation, a second hexagonal close-packed monolayer was successfully deposited on top of the first one (SEM in Fig. ). Interestingly, crystallization at the a/w interface -and not on the previously formed crystalline structure -allowed to keep domains orientation and inter-particle distances independent between first and second deposition, a characteristic not easily accessible when particles directly assemble on structured substrates. The independence of domains orientations between the first and second layer resulted in Moiré interference patterns when the two overlaid monolayers assembled with a small angle displacement (see arrows in Fig. ). We next explored the sequential deposition of particles of different sizes in order to produce layered colloidal crystal "alloys". Deposition of 560 nm particles on 977 nm ones (Figs. 4d, S10a), or 977 nm particles on 2.4 μm ones (Fig. ), also led to final crystalline structures in which the assembly of the second layer was independent of the underlying one. The upper layer maintained the same long-range order both on the bare substrate and on top of the first particle layer (SEM in Fig. ), where few more defects resulted from the higher roughness of the surface underneath. Overall, this indicates that the monolayers could be deposited also on substrates of complex topologies while keeping their longrange close-packed order achieved during the particles self-organization at the fluid interface.