Nanofiber-coated conductive filaments, made by electrospinning, can be used extensively in various electronic applications, such as membranes for manufacturing fiber-shaped batteries and supercapacitors. However, research on the fiber coating mechanism is necessary in order to be able to control the surface morphology and thickness of coated layers. In this study, fiber-shape coated layers of poly(vinyl alcohol) were electrospun onto conductive filaments. The jet behaviors at various nozzle-to-collector distances were observed using charge-coupled devices and high-speed cameras. The mechanism of the coating process was determined from visible evidence and an appropriate coating model is suggested. Differences in jet behavior induce differences in the coating location on the filament surface. Consequently, the surface morphology and the thickness uniformity of the coated layer are changed. (c) 2017 Society of Chemical Industry