Standard electrospray and nanospray are often defined in terms of flow rates (arbitrarily set at several µL/min for electrospray vs. in the nL/min range for nano-electrospray). However, the source regime, a notion beautifully reviewed recently , could be relevant to the ion production regime and to internal energy differences. All high-flow sprays requiring a nebulizing gas to aid droplet desolvation and gas-phase ion production fall into the jetting regime, where the droplets are not well-calibrated. In contrast, in nano-capillary electrospray (static nano-electrospray), a cone-jet mode is established wherein the electrophoretic current suffices to sustain the production of monodisperse droplets charged close to the Rayleigh limit.