A printing device and a control method for a printing device can freely change the distribution of print data to the front and back sides to achieve the desired duplex printing result when operating in a duplex printing page mode that converts the print data for one page after setting the data conversion area. A conversion step (step S29) sets a break length hy that divides the data conversion area 105c into a first data storage area 105a for converting the first-side print data and a second data storage area 105b for converting the second-side print data in the page mode, and then converts the print data. A print step (step S36) then simultaneously prints the first-side or front print data that is converted into the conversion area before the break, and the second-side or back print data that is converted into the conversion area after the break.