Figure 3 - The inking process that arranges the particles.

a, The meniscus of a colloidal suspension containing 60-nm Au particles is moving over the patterned PDMS surface of a printing plate. b, Simulation of the evaporation (colours indicate concentrations) and the streamlines (red lines) of the laminar flow that drags along particles towards the three-phase contact line, where they form an accumulation zone. The main panel is a simulation at a relative humidity (RH) of 50% and the inset for a RH of 95%. c,d, The accumulation zone, visible in the micrographs as a bright yellow line, moves over the printing plate. Depending on the geometry they encounter, particles at the contact line form sparse patterns, for example, arrays (c) or dense arrangements such as lines (d).