A method of preparing a polymer article comprising determining a zero-shear viscosity for a polymer sample; sieving the polymer sample to produce a plurality of sieved polymer samples; determining a molecular weight distribution for each of the plurality of sieved polymer samples; determining a zero-shear viscosity for each of the plurality of sieved polymer samples; determining a compositional diversity of each of the plurality of sieved polymer samples based on a ratio of the zero shear viscosity for each of the plurality of sieved polymer samples to the zero shear viscosity for the polymer sample; identifying a polymer sample having a ratio of the zero shear viscosity to zero shear viscosity for the polymer sample of from about 0.5 to equal to or greater than about 3; and preparing a polymer article from the identified polymer sample.