The invention relates to a developing method in a printing apparatus containing distributed electricity on a photo-sensitive element; exposing the photo-sensitive element to form a first latent image on the photo-sensitive element; developing the first latent image through a first developing element having a first potential to form a first carbon powder image; removing electricity to the photo-sensitive element having the first carbon powder image, so that the first carbon powder image on the photo-sensitive element has a second potential which is generally equal to the first potential of thefirst developing element.