Method of multi-color pagewide printing with optimized nozzle hydration

1. A method of multi-color printing in a single pass using a fixed pagewide array of monochrome inkjet printheads, the printheads being aligned with each other in a media feed direction, the method comprising the steps of:

feeding print media along the media feed direction past a first printhead positioned furthest upstream in the array, a third printhead downstream of the first printhead and a second printhead positioned furthest downstream in the array;

printing a yellow ink onto the print media using the first printhead;

printing a black ink onto the print media using the third printhead; and

printing a cyan or magenta ink onto the print media using the second printhead,

wherein:

each of the first, second and third printheads prints a respective keep-wet pattern onto print media;

each keep-wet pattern is defined by a plurality of dots printed at a frequency sufficient to maintain hydration of each nozzle of a respective printhead;

all nozzles of the first printhead print a first keep-wet pattern at a first average frequency, all nozzles of the second printhead print a second keep-wet pattern at a second average frequency, and all nozzles of the third printhead print a third keep-wet pattern at a third average frequency; and

the first average frequency is higher than the third average frequency.

2. The method of claim 1 , further comprising the steps of:

feeding the print media past a fourth printhead positioned between the first and second printheads; and

printing a magenta or cyan ink onto the print media using said fourth printhead.

3. The method of claim 1 , wherein the first average frequency is higher than the second average frequency.

4. The method of claim 1 , wherein the print media is fed past the array at a speed of greater than 0.2 meters per second.