instability or other problems there is no particular lower limit of z x although minimum levels contemplated by the instant invention are levels greater than trace or incidental amounts generally there is at least about 2 ppm commonly at least about 4 ppm and even 10 ppm or more of multivalent in the ink likewise there is no particular upper limit except as dictated by stability or other ink properties at some level though there is no additional od gain with increasing z x in some cases too much z x may cause the od to decrease again in general beneficial effects are achieved with less than about 200 ppm of z x and typically even less than about 100 ppm although the preceding discussion of z x in terms of weight percent is provided for the sake of simple concrete guidance it will be appreciated from the examples herein after that the appropriate levels of multivalent cations are related in a more complex way to factors such as molar equivalents atomic weight valence state and also to the amount sdp in the ink and its level of treatment thus a preferred method for considering multivalent cation content is by adjusted equivalents of z x per 100 equivalents of surface function the amount of z present is adjusted multiplied by the valence state x an equation can be written as follows adjusted u2062 u2062 u2062 z u2062 u2062 per u2062 u2062 100 u2062 u2062 surface u2062 u2062 function u2062 100 u2062 u2062 equivalents u2062 u2062 z u2062 u2062 x equiv u2062 u2062 of u2062 u2062 surface u2062 u2062.