We have prepared a 10 vol% zirconium oxide (ZrO2) powder aqueous ink for ink-jet printing. This ink shows severe segregation or coffee staining during drying on solid substrates. Coffee staining is suppressed by the addition of 10 wt% poly(ethylene glycol) (PEG) to the ink formulation. However, coffee staining occurs with the PEG solution ink when drops are printed onto a substrate made from a preprinted ZrO2 powder layer. The mechanism for this phenomenon remains unknown but may be related to the draining of solvent into the powder. The stability of printed features is controlled by the overlap of printed drops and the range of line stability is shown to be consistent with models in the literature.