To compensate for plate distortion on press cylinders, you must apply a scaling amount when outputting flexo plates. Plate distortion, also known in flexography as plate elongation, refers to the image distortion that occurs on a flexo plate that is mounted on press. The distortion occurs when the flexible plate is wrapped around a curved press cylinder because the outside plate surface (the side from which the image is printed) is stretched, while the inside surface is compressed. A circle, for example, will distort into an oval when the plate is wrapped around the cylinder (see the diagram below).
The amount of distortion that occurs depends on several factors, such as the repeat length of the cylinder, the thickness of the plate, and the plate type. However, the most significant of these factors are plate thickness and repeat length.
Note: The smaller the repeat of the cylinder, the more that the image is distorted (due to the outside surface of the plate being stretched more).
Plate distortion