A method for applying flame treatments to a print surface on an object in an inkjet printer includes activating a hydrogen torch within the inkjet printer to generate a flame through a nozzle of the hydrogen torch and operating an actuator to move at least one of the print surface or the nozzle in a predetermined direction to apply the flame from the nozzle to the print surface. The method further includes adjusting a rate of fuel flow to the nozzle of the hydrogen torch to change a thermal output level of the flame with reference to a change in distance between the nozzle of the hydrogen torch and the print surface during the operating of the actuator.