Compared to the same experiments done with the hanging drop (Fig. , dp = 560 nm), the final deposit was composed of a large number of much smaller domains exhibiting structural colours. In that case, particles reaching the descending interface upon evaporation could adsorb, thus forming a monolayer, but the confinement could only be achieved very locally by the collective sinking of particles deforming the interface against its curvature and explaining the formation of domains of micrometer size only. Hanging the drop had thus a dual role of both accelerating the transport of particles to the interface and favouring long-range order by gravity-driven confinement in the convex fluid interface. While adsorption of particles at the fluid interface is necessary to obtain the 2D confinement leading to selfassembly of an ordered monolayer, the interface geometry itself may play an important role in the final deposit morphology. We were expecting the packing force to increase with particle weight and interface curvature, while evaporation might counteract this phenomenon by creating surface flows toward the drop edges. Both phenomena were strongly influenced by contact angle and pinning of the contact line, and were explored using different substrates with the typical drop composition (silica particles, dp = 560 nm, Cp = 0.05 mg/mL, Cs = 10 μM). First, using polydimethylsiloxane (PDMS) substrate, a drop with increased contact angle was obtained (θc = 106°). In this configuration, the higher curvature was assumed to increase the gravity-based compressive forces driving the monolayer crystallization, and to reduce the opposing recirculating flows (Fig. ). Accordingly, the obtained deposit showed numerous long-range ordered domains (Fig. ). The relatively small size of domains might be attributed to a faster packing process, which froze boundaries between adjacent crystallites formed at an early stage. The presence of larger domains at the periphery, where compression is lowered and packing more progressive, confirms this hypothesis. Wrinkles propagating throughout the assembly were also observed on the deposit, revealing excessive compressive forces when the diameter of the drop equalled the one of the particles monolayer during the last stage of evaporation (Movie S6). In contrast, when the drops were deposited on a glass substrate (θc = 52°), the lower interfacial curvature and stronger evaporation flows at the drop edge led to short-range ordered structures with numerous defects and voids (Figs. and), presumably due to the lower compression forces. However, the weak packing observed on a hydrophilic substrate could be circumvented by using larger particles, thereby increasing compressive forces and the quality of the crystalline deposit (Figs. and). Similar to drop curvature, we hypothesized that increasing particles number (Np) would affect the structural arrangement in the deposits, either by increasing compaction forces or by adding topological stresses on larger assemblies. To assess the sizes of deposits achievable with our method, and further understand the role of Np on the monolayer morphology, we first varied the particles concentration at a fixed drop volume of 5 µL and a constant surfactant concentration Cs = 10 μM (silica particles, dp = 560 nm). When increasing Cp from 0.025 to 0.4 mg/mL (Fig. , conditions 2-5), we observed an expected increase in the disk size (diameter Ddisk ranging from 0.5 to 1.2 mm), but also an increase in the number of monocrystalline domains. This change in deposit morphology was attributed to the collective weight of the particles assembling at the centre, hence increasing the local surface deformation, and also to geometrical constraints between the 6fold coordinated monolayer and the curved surface so to lower the total energy of the system. Below a number of particles Np = 2•10 6 , the deposit area increased almost linearly with Np and could be compared to the theoretical deposit area for a close-packed assembly (Fig. , blue dots). However, when working at fixed drop volume this relationship was lost for high Np, leading to smaller deposits than expected with more and more particles depositing on top of the ordered monolayer and wrinkles in the structure (Fig. , image 5). This limitation could be circumvented by increasing the drop volume Vdrop at fixed Cp (Fig. , images 1; 3; 6 and Fig. , red dots). Larger assemblies could be obtained with the majority of particles in an ordered monolayer, maintaining the linear relationship between particles contained in the drop and the size of the final deposit. Note that a linear relationship was also found between the initial drop area and the final deposit area (Fig. ). A maximum deposit area of 1.27 mm 2 was obtained for Vdrop = 15 μL, the higher Vdrop that could be used to form and flip drops that remained held on the substrate. However, the drop volume could be further increased by using a modified technique: first, a 5 μL drop was deposited on the solid substrate and flipped, then an additional volume of the same particle suspension was injected into the flipped drop until the required Vdrop was reached. This allowed to increase almost linearly the final deposit area up to 3.1 mm 2 for a maximum Vdrop = 55 μL (Fig. , grey points), but with the occurrence of wrinkles and multilayered regions in the centre and at the periphery of the deposit. Conversely, decreasing Np (either via Cp or Vdrop) led to the assembly of almost monocrystalline deposits, as characterized by a single structural colour in the reflection images (Fig. , images 1; 2). All these results emphasize the versatility of this deposition method through the variety of particle type (silica, PS), particle size (from few hundreds of nm to several µm) and substrate nature (PS, PDMS, glass) that can be used, and highlight the degree of control in deposit size and crystalline arrangements achievable through the adjustment of user-accessible parameters, in particular particle concentration, drop volume and drop curvature through substrate wetting property.