A novel mapping method presented analyzes the long-term efficiency of distributive mixing in Stokes flows. It uses the results of an accurate front tracking technique to calculate a distribution or mapping matrix For the first time, it is possible to efficiently investigate the influence of geometric configurations and operating conditions on overall mixing quality. The technique was tested using the mixing dynamics of a model time periodic prototype flow; namely Stokes flow in a 2-D, lid-driven cavity. The method however; can also be extended to examine more realistic spatially periodic flows such as static mixers or twin screw extruders.