We give a concise overview of nanoparticle array formation by wet coating techniques including patterned assembly, surface modification of nanoparticles, rheology, assembling dynamics, and function of nanoparticle arrays. For the rapid fabrication of large-area and/or patterned nanoparticle arrays, wet coating techniques, such as spin, dip, spray, gravure, slot, roll, and ink-jet coating, are promising ways for practical use in combination with an evaporation-driven self-assembly technique. We have also referred to the concept of array formation via surface modification.