Coating plates defines a plate that applies a very even varnish, gloss finish, or primer over a large area. There are two type of coating plates. One is used for Flexo and the other is for Litho.A Flexo coating plate is just a plate the transfers its coating very evenly. It is mounted to the cylinder using sticky back. Sometimes the ink used is very aggressive and reacts with the photopolymer in detrimental  ways. The  plate material is selected based on the environmental conditions it is being used.A  Litho plate coating plate is in reality a Flexo plate with special attributes. First, it must have a 0.010 inch backing. Because the coating plate is gripped at the leading and trailing edge and pulled tight around the drum, the backing must be strong enough to accept the stretch without tearing. Traditionally for litho presses the plate overall thickness is 0.045 inches and is washed down to the floor. Because this is a special requirement, it is not found in standard 0.045 inch flexo plates. Plate requirements regarding ink have the same requirements as do Flexo coating plates.Coating plates have a distortion factor applied. Flexo plates are distorted in the traditional way based in cylinder diameter and plate thickness. Litho plates are distorted based on the ruler test.  A non distorted plate with a ruler imaged onto the plate is mounted on the cylinder. The packing under the plate  is recording along with a measurement using a torque wrench of jaw tension. The plate prints to paper which is then measured. The printed ruler is measured against a ruler image printed from a offset station. the distortion is calculated so that the two ruler images are equal. We have had experience with both water-wash and solvent plates. Each plate type has special properties that make it the best solution for a specific application.