This invention relates to a printer whereby ink is printed by being discharged as dots from a plurality of nozzles by means of pulses. To ensure high quality printed images it is necessary to ensuring that the size of all dots is consistent. Therefore there is provided a method and apparatus whereby before printing of any dots, the temperature of the ink in each nozzle is sensed by Tsense, and the pulse duration is varied in response to the temperature of the ink to ensure consistent dot size.