1. A method for aligning at least two flexographic printing plates on respective printing cylinders, wherein each printing plate has raised parts for creating corresponding parts of a graphical motif to be printed with a particular color, said method comprising the steps of: placing a first plate on a respective first cylinder and placing the first cylinder on a bench under at least one image acquisition device; acquiring a first image of the raised part of the first plate by means of said at least one image acquisition device; memorizing the first image; memorizing at least one electronic, mechanical or optical parameter with which said first image was acquired; memorizing the position of said at least one image acquisition device at which said first image was acquired; associating a memorized parameter with said memorized position; removing said first cylinder from said bench; placing a second plate on a respective second cylinder and placing the second cylinder on the bench under said at least one image acquisition device; positioning said at least one image acquisition device at said memorized position and configuring said image acquisition device to the memorized parameter; contemporaneously displaying the memorized first image having the raised part of the first printing plate with a second image having the raised part of the second plate that is acquired in real time by the image acquisition device at the memorized position with the memorized parameter; and visually aligning the second image with the first image by moving the second plate on the second cylinder so that the image of the raised part of the second plate is drawn together with the image of the raised part of the first plate, thereby aligning the second plate with the first plate.