We present the main printer calibration procedures for HP Page Wide XL 4/8000 page wide array (PWA) printer. They ensure consistent, uniform printouts by calibrating print elements to each other, both for relative positioning and relative colorimetric densities. Requirements for (PWA printers are much stricter than for scanning printers, and for that, new solutions have been devised. Furthermore, in large format PWA printers there are more restrictions for the carriage subsystem that include the calibration sensors, so that the trajectory of sensors relative to the calibration patterns is less accurate than in scanning printers. We present the new print-head alignment strategy and detailed patterns innovations to overcome the challenges in scanning trajectory and at the same time meeting the precision requirements. Innovations comprise the use of new position based patterns, to obtain a fast and wide error range "coarse grained" measurement, in combination with high precision interferential patterns that refine the final measurements. Colorimetric calibration includes novelties such as using floating references to make sure almost all available media can be calibrated, in opposition to past calibrations that used references defined in absolute domains. Furthermore, it incorporates means for reusing a calibration run on a given paper to the rest of paper types loaded in the printer. All of that ensures maximum color deltas between adjacent print elements in the order of 0.5dL*, with percentile 95 in the order of 0.2dL* (data obtained in selected paper types). The solutions for the problems derived from the incompleteness of calibrations when the media used does not cover the full printing region are also presented. To enable a satisfactory user experience in a variety of media usage scenarios in a multi-roll printer a number of innovations have been introduced, ranging from the use of print-head module manufacturing data to the optimal selection of the media roll to calibrate when different media qualities and widths rolls are loaded in the printer. The presentation covers the basic concepts of print-head positioning and colorimetric calibrations, and then reviews novel solutions adopted in HP page wide array technical printers.