Printer and supply unit for use in the printer

A printer which consists essentially of a print unit,

• a supply unit for a supply of substrate,
• and a transport unit deposed between the supply unit and the print unit, said transport unit controlling the tension in the web, wherein
• said supply unit includes a first holder for rotatably receiving a first web of a first substrate wound into a first roll, and a second holder for rotatably receiving a second web of a second substrate wound into a second roll,
• a first motor directly operatively connected to the first roll for driving the first roll such that the first web of the first substrate is unwounded from the first roll
• a second motor directly operatively connected with the second roll for driving the second roll such that the second web of the second substrate is unwounded from the second roll,
• an actuating unit for actuating the motors and
• a common switch for selectively connecting the actuating unit to the first or second motor, and a control unit, by means of which the switch connects the actuating unit to the first motor when the printer is configured for printing a first substrate, and the switch connects the actuating unit to the second motor when the printer is configured for printing the second substrate, whereby mutual exclusiveness of activation is achieved.