Then, these average thickness values were plotted in a thickness vs. concentration graph as well give the thickness of spin coated polymer thin-films as a function of variables such as viscosity, evaporation rate, spin speed/time, liquid density, etc. . In the present model, all factors are kept constant besides molecular weight and concentration, which primarily affect viscosity, binary diffusivity, and evaporation rate, which in turn affect the thickness of the final spin-coated film.