Ink distribution to the transfer roller of a printing machine is rapidly influenced. The ink duct roller is driven at a maximum speed and the ink distribution roller is caused to rotate at the ink duct roller speed. The ink vibrator roller is brought ink continuous engagement with these two rollers and is brought out of contact with its oscillating drive mechanism. The ink fountain is closed and excess ink is conveyed back to it. The original speeds of the ink duct roller and the ink distribution roller are re-established and the oscillating drive of the vibrator roller is resumed.