Visualization of the series of events and physical processes in inkjet printing, from the ink–piezo actuator interaction (left), via ink jetting (middle), to the interaction between ink and the receiving substrate (right). The circled numbers refer to the seven fundamental fluid dynamics challenges referenced in the sections of this review: (❶) the flow and acoustics in the inkjet printhead; (❷) bubbles that are entrained into the nozzle and disturb the printing operation; (❸) the wetting dynamics on the nozzle plate, including the meniscus, droplet, and film dynamics; (❹) the jetting process, including satellite formation; (❺) the drop impact and spreading on the substrate; (❻) drop coalescence, drop–film interaction, and ink–paper interaction; and (❼) the evaporation and solidification of the ink. Image and caption: Annu. Rev. Fluid Mech. 2022. 54:349–82