A grayscale image is printed on the polyester plate using a laser printer or drawn with an oily medium like litho crayon, tusche or ball point pen. The plate is heated to 200 degrees to set the image. Water, with a mixture of gum arabic and citric acid is sponged over the plate. Oil base ink is then rolled over the plate.
The water/gum mixture sticks to the plate, but will not stick to the laser image or drawing. The oil based ink sticks to the oily drawing or laser image, but not to the gum/water solution coating the rest of the plate.
The resulting print can be distinguished from many other types of hand pulled prints (like solar plates or etchings) by its lack of an indentation around the edges of the plate.