In a more practical light, the results and techniques presented in this study allow defining optimal buffer solutions which might or might not be feasible when considering the actual pK a values of monovalent species. However, finding combinations of real weak acids that come as close as possible to such optima will lead to solutions with improved buffer-index stability over a wider range of pH and can serve as a guide for buffer preparation that do not aim at pH ranges wider than 3 pH units.