The drainage behavior of a wide variety of non‐Newtonian liquids has been studied under circumstances when “free‐drainage” conditions apply. Experimental values for the time‐variant film thicknesses were obtained while drainage proceeded using a light absorption technique, and an analytic expression relating film thickness to drainage time was derived for fluids described by the Ellis model. Deviations between the experimental and theoretical results are interpreted in light of the Ellis model's inability to describe the elastic properties of the liquids studied.