PURPOSE: To simultaneously perform printing of front and rear faces so as to speed up a printing process by regulating tension on machine glazed paper and uniformly retaining the same.

CONSTITUTION: The controlling device for paper controls electric power for a driving motor in the inside of a printer by which machine glazed paper 32 is moved so as to pass through the printer. A motor 55 is energized by a speed sense and torque generator 58 through a lead wire 62. Electric power controlled by the circuit 58 is given to the DC motor 55. The motor gives counterclockwise torque to a main axis 57 through an output axis and a driving belt 56. This counterclockwise torque is given to a paper roll 13. Before the other motor of the printer is energized, loose of paper is rewound. As paper on a roll 13 is used up, constant tension is caused on the machine glazed paper 32. Similarly, even in the printing mechanisms 14, 15, image transfer drums 43, 47 are rotated counterclockwise by rotation of motors 33, 38 and the machine glazed paper 32 is passed through the printing mechanisms 14, 15 and pulled in the advancing direction.