c 1 except 0 90 sodium acetate aldrich was added one liter of ink was prepared like control ink c 1 except 3 53 tetrabutylammonium bromide aldrich was added one liter of ink was prepared like control ink c 1 except 1 11 sodium bromide em science was added each of the above inks was filled into a reservoir of an encad 700 printer and into an empty encad gs ink cartridge an image quality target that contained a small 2 0 square cm magenta patch was printed onto kodak professional ei premium media and the initial density was measured using an x rite densitometer a prime target was printed to make sure all of the nozzles were firing correctly and there were no electrical failures an electrical failure may occur when there is either an electrical short to ground so that the heater is by passed and insufficient heat is generated in the heater or there is a significant increase in resistance in the heater circuit which would also inhibit generation in the heater in the printhead either of these phenomena causes the nozzle not to operate a large 100 magenta patch target 92 by 610 cm was then printed that consumed 25 ml of ink a second image quality target was printed onto kodak professional el premium media and the density was re measured a prime target was printed to make sure all of the nozzles were firing correctly and there were no electrical failures this test was repeated until a total of 300 ml of ink was fired through a single encad printhead the percent density retained between.