In nanotechnology research, the generation of a single-grain nanostructure with a long-range lateral order is challenging. In this presentation, we report upon a new solvent-annealing method using a double-sandwich confinement to promote the formation of a large-area, single-domain array of supramolecular cylinders. Two key factors were found to be crucial in this process for generating highly-ordered supramolecular building blocks: i) the presence of a top coat during solvent evaporation and ii) the control of the solvent evaporation rate during the solvent evaporation step.