An inkjet printing system (40, 500), comprising: an inkjet printhead (10, 510) comprising an ink via and a plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8), the plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8) being arranged in columns (L, R) on opposing sides of the ink via and the columns (L, R) being vertically offset from one another; an ink reservoir connected to deliver ink to the inkjet printhead (10, 510); a fire count detection system that is configured to detect a number of times the inkjet printhead (10, 510) has been activated to eject ink from one or more of the plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8); an ink height calculation system that is configured to determine a height of ink remaining in the ink reservoir based on the fire count (x) detected by the fire count detection system; a time period detection system that is configured to determine a period of time between a last inkjet printhead activation time and a current inkjet printhead activation time; an ink concentration calculation system that is configured to determine a pigment concentration of ink ejected by the inkjet printhead (10, 510) relative to an initial pigment concentration of the ink based on the determined height and the determined period of time; an activation controller configured to generate nozzle activation signals; and a control module operatively connected to receive information from the ink height calculation system, the time period detection system and the ink concentration calculation system and configured to determine based on the information a firing pattern for the inkjet printhead (10, 510) and to cause the activation controller to generate the nozzle activation signals based on the determined firing pattern, the control module being configured to determine, upon a condition that the control module determines that the relative pigment concentration is 1.0, a firing pattern that results in a dot coverage over a first percentage of a print medium area, and the control module being configured to determine, upon a condition that the control module determines that the relative pigment concentration is greater than a predetermined amount over 1.0, a firing pattern that results in a dot coverage over a second percentage of the print medium area, the second percentage being less than the first percentage. an inkjet printhead (10, 510) comprising an ink via and a plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8), the plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8) being arranged in columns (L, R) on opposing sides of the ink via and the columns (L, R) being vertically offset from one another; an ink reservoir connected to deliver ink to the inkjet printhead (10, 510); a fire count detection system that is configured to detect a number of times the inkjet printhead (10, 510) has been activated to eject ink from one or more of the plurality of inkjet nozzles (L 1 -L 8, R 1 -R 8); an ink height calculation system that is configured to determine a height of ink remaining in the ink reservoir based on the fire count (x) detected by the fire count detection system; a time period detection system that is configured to determine a period of time between a last inkjet printhead activation time and a current inkjet printhead activation time; an ink concentration calculation system that is configured to determine a pigment concentration of ink ejected by the inkjet printhead (10, 510) relative to an initial pigment concentration of the ink based on the determined height and the determined period of time; an activation controller configured to generate nozzle activation signals; and a control module operatively connected to receive information from the ink height calculation system, the time period detection system and the ink concentration calculation system and configured to determine based on the information a firing pattern for the inkjet printhead (10, 510) and to cause the activation controller to generate the nozzle activation signals based on the determined firing pattern, the control module being configured to determine, upon a condition that the control module determines that the relative pigment concentration is 1.0, a firing pattern that results in a dot coverage over a first percentage of a print medium area, and the control module being configured to determine, upon a condition that the control module determines that the relative pigment concentration is greater than a predetermined amount over 1.0, a firing pattern that results in a dot coverage over a second percentage of the print medium area, the second percentage being less than the first percentage.