MacCormack’s predictor-corrector algorithm is used to solve one-dimensional model equations of drop development from a drop-on-demand ink jet. The calculation is done in Lagrangian coordinates, and the results are compared with calculations reported in which an axisymmetric marker-and-cell algorithm is used. The comparison indicates that, although drop velocities differ in the two cases, good qualitative results can be obtained with the less complex one-dimensional approach.