1. A printing apparatus comprising: a print head that includes a plurality of nozzles including lower-end portion nozzles, center-portion nozzles, and upper-end portion nozzles; a medium transport unit that transports a medium that becomes a printing target; an edge detecting unit that detects an image boundary edge included in image data; and a print control unit that forms a row of dots on the medium by driving the print head together with relatively moving the print head and the medium, the row of dots being formed on the medium by using at least two different nozzles of the plurality of nozzles, wherein the number of different nozzles used is a first number in a case where the row of dots does not correspond to an image boundary edge detected by the edge detecting unit and the row of dots can be formed at least in part by one of the upper-end portion nozzles and one of the lower-end portion nozzles, and wherein the number of different nozzles used is a second number that is smaller than the first number where the row of dots corresponds to an image boundary edge detected by the edge detecting unit and the row of dots can be formed at least in part by one of the upper-end portion nozzles and one of the lower-end portion nozzles.