The flow curves for four water‐soluble, non‐ionic polymer types have been characterized using rotational viscometers primarily. Molecular weight and solution concentration variations gave a total of twenty‐five curves. Polyacrylamide, poly(ethylene oxide), hydroxyethyl cellulose, and methyl cellulose were studied. A two‐parameter model that gives a good fit to the data over five decades of shear‐rate is:log (ηr)/log (ηr)0=0.68−0.32 erf {[log (τγ̇)−log B]/2.272}In this equation,ηris the relative viscosity;(ηr)0,the same at zero shear‐rate, erf, the error function;(τγ̇),the rate of energy dissipation; and,B, the value of(τγ̇)at the inflection point of the flow curve. Furthermore,Bis independent of concentration.