To understand the effects of liquid viscosity and surface wettability on the outcomes for a drop impacting perpendicularly on a dry, clean surface at a normal temperature and pressure, experiments were conducted for a wide variety of droplets and substrate surfaces. These experiments included a range of receding contact angles (from ~18° to ~150°) and liquid viscosities (from 1 cp to 45 cp); the broadest such combination is yet published. The surface wettabilities were quantitatively characterized using a new set …