A printing apparatus comprising: a carriage capable of reciprocating in a scanning direction; a printing device mounted on the carriage and including a plurality of printing elements to form dots on a print medium by applying ink droplets while scanning the carriage in the scanning direction; a conveyance member configured to convey a print medium in a conveyance direction crossing the scanning direction; a plurality of platen ribs configured to be arranged on a conveyance route of a print medium at positions facing the printing device at predetermined pitches in the scanning direction and to support the print medium, a reflection-type optical sensor configured to be movable in the scanning direction by the carriage, and to read an image on the print medium, a controller configured to control the printing device, wherein the printing device is configured to print an adjustment pattern on a print medium in response to reception of an instruction to adjust print positions of ink droplets to be applied by the printing device, the adjustment pattern including a first plurality of patches and being for use for adjustment, the printing device is further configured to print the adjustment pattern such that two or more patches are printed next to each other in the scanning direction in a neighboring area around a certain one of the plurality of platen ribs and that no patches are printed in a middle area between the certain platen rib and another platen rib next to the certain platen rib in the scanning direction, characterized in that prior to printing of the adjustment pattern, the printing device prints a coarse adjustment pattern for adjusting print positions of the dots with more coarse accuracy than that of the adjustment pattern, wherein a second plurality of patches included in the coarse adjustment pattern is arranged irrespective of the positions of the plurality of platen ribs, and the controller obtains a reading result of the coarse adjustment pattern using the reflection-type optical sensor and controls the printing device to change the print positions of the dots in the first plurality of patches in the adjustment pattern based on the reading result. a carriage capable of reciprocating in a scanning direction; a printing device mounted on the carriage and including a plurality of printing elements to form dots on a print medium by applying ink droplets while scanning the carriage in the scanning direction; a conveyance member configured to convey a print medium in a conveyance direction crossing the scanning direction; a plurality of platen ribs configured to be arranged on a conveyance route of a print medium at positions facing the printing device at predetermined pitches in the scanning direction and to support the print medium, a reflection-type optical sensor configured to be movable in the scanning direction by the carriage, and to read an image on the print medium, a controller configured to control the printing device, wherein the printing device is configured to print an adjustment pattern on a print medium in response to reception of an instruction to adjust print positions of ink droplets to be applied by the printing device, the adjustment pattern including a first plurality of patches and being for use for adjustment, the printing device is further configured to print the adjustment pattern such that two or more patches are printed next to each other in the scanning direction in a neighboring area around a certain one of the plurality of platen ribs and that no patches are printed in a middle area between the certain platen rib and another platen rib next to the certain platen rib in the scanning direction, characterized in that prior to printing of the adjustment pattern, the printing device prints a coarse adjustment pattern for adjusting print positions of the dots with more coarse accuracy than that of the adjustment pattern, wherein a second plurality of patches included in the coarse adjustment pattern is arranged irrespective of the positions of the plurality of platen ribs, and the controller obtains a reading result of the coarse adjustment pattern using the reflection-type optical sensor and controls the printing device to change the print positions of the dots in the first plurality of patches in the adjustment pattern based on the reading result.