A method of generating a diagnostic plot for a printing system, comprising: printing, with a first printhead die, a first half (80A, 80B) of a diagnostic pattern representative of a first state of the printing system; and printing, with a second printhead die adjacent the first printhead die, a second half (80C, 80D) of the diagnostic pattern representative of a second state of the printing system; wherein printing the first half of the diagnostic pattern comprises printing a first half of a color calibration pattern, printing the second half of the diagnostic pattern comprises printing a second half of the color calibration pattern, the first half of the color calibration pattern is printed from the first printhead die, the second half of the color calibration pattern is printed from the second printhead die being adjacent the first printhead die, and the diagnostic pattern includes a circle divided into four quadrants, further wherein quadrants corresponding to an upper half and a lower half of the first half (80A, 80B) of the color calibration pattern respectively represent different color threshold values of the first printhead die, and quadrants corresponding to an upper half and a lower half of the second half (80C, 80D) of the color calibration pattern respectively represent opposite color threshold values of the second printhead die, such that a quadrant corresponding to the lower half of the first half and a quadrant corresponding to the upper half of the second half have the same color value, corresponding to a first lightness value, and a quadrant corresponding to the upper half of the first half and a quadrant corresponding to the lower half of the second half have the same color value corresponding to a second lightness value, wherein a color difference between a quadrant corresponding to the lower half of the first half and a quadrant corresponding to the upper half of the second half, and a color difference between a quadrant corresponding to the upper half of the first half and a quadrant corresponding to the lower half of the second half respectively, is a maximum value that produces a non-noticeable difference when the printing system is within predetermined specifications, wherein a variation of the diagnostic pattern indicates that the printing system is out of specification, said variation of the diagnostic pattern comprising a change in pattern of the quadrants of the circle, corresponding to a noticeable difference. printing, with a first printhead die, a first half (80A, 80B) of a diagnostic pattern representative of a first state of the printing system; and printing, with a second printhead die adjacent the first printhead die, a second half (80C, 80D) of the diagnostic pattern representative of a second state of the printing system; wherein printing the first half of the diagnostic pattern comprises printing a first half of a color calibration pattern, printing the second half of the diagnostic pattern comprises printing a second half of the color calibration pattern, the first half of the color calibration pattern is printed from the first printhead die, the second half of the color calibration pattern is printed from the second printhead die being adjacent the first printhead die, and the diagnostic pattern includes a circle divided into four quadrants, further wherein quadrants corresponding to an upper half and a lower half of the first half (80A, 80B) of the color calibration pattern respectively represent different color threshold values of the first printhead die, and quadrants corresponding to an upper half and a lower half of the second half (80C, 80D) of the color calibration pattern respectively represent opposite color threshold values of the second printhead die, such that a quadrant corresponding to the lower half of the first half and a quadrant corresponding to the upper half of the second half have the same color value, corresponding to a first lightness value, and a quadrant corresponding to the upper half of the first half and a quadrant corresponding to the lower half of the second half have the same color value corresponding to a second lightness value, wherein a color difference between a quadrant corresponding to the lower half of the first half and a quadrant corresponding to the upper half of the second half, and a color difference between a quadrant corresponding to the upper half of the first half and a quadrant corresponding to the lower half of the second half respectively, is a maximum value that produces a non-noticeable difference when the printing system is within predetermined specifications, wherein a variation of the diagnostic pattern indicates that the printing system is out of specification, said variation of the diagnostic pattern comprising a change in pattern of the quadrants of the circle, corresponding to a noticeable difference.