The analysis proposed earlier by us for the evaluation of the contrast of diazo-type positive photoresists is extended to include the influence of standing waves and post-exposure bake. The dependence of the contrast on a large number of processing variables including exposure dose, development time, developer concentration, pre-and post-exposure thermal treatment, etc. is evaluated. For a substrate that is optically matched with the photoresist, however, the evaluation of contrast is exact and more direct using the recently derived closed form solution of Dill's equations. Further, assuming that the resist development occurs in two stages, first down to the substrate and then away from the center line, the variation of linewidth with the development time has been calculated for AZ1370 resist for a given aerial image intensity distribution across the resist surface. If the resist development occurs predominantly in the downward direction, then it is shown that the slope of the line channel sidewall is proportional to the contrast.