Patent ID: 7101016

Claim:
A method comprising: determining a plurality of calibration factors for a fluid-ejection mechanism capable of ejecting a plurality of differently colored fluids by outputting a plurality of multiple-color fluid targets via fluid ejection by varying a number of fluid drops ejected of each of the plurality of fluid colors of each multiple-color fluid target, each multiple-color fluid target having a different combination of a plurality of fluid colors; and, determining a most color-neutral target of the plurality of multiple-color fluid targets, such that the energy used to eject fluid for each of the at least one of the plurality of fluid colors is adjusted based on the most color-neutral target; and adjusting an enemy used to eject fluid for each of at least one of the plurality of fluid colors based on the plurality of calibration factors so that fluid drop ejections of the plurality of fluid colors yield fluid drop masses having a consistent ratio by determining the number of fluid drops elected for the fluid color on the most color-neutral target; and adjusting the energy used to eject the fluid for the fluid color based on the number of fluid drops ejected for the fluid color on the most color-neutral target compared to a reference number of fluid drops that should have been ejected to ensure color neutrality by adjusting the energy used to eject the fluid for the fluid color based on a linear relationship between energy and drop mass for the fluid color.