Printing Plate Etch
Plate etch is a lightweight wetting solution that is often manually wiped onto the plate just after a plate is loaded. The purpose of Etch is twofold, the first and most important role is to help with the wetting process of the plate. Printing plates in offset printing must be sufficiently moist in order to properly pick up and transfer ink. Etching a plate just after it is loaded will supply a baseline of moisture onto the plate to help speed up the process of coming up to color. The second function of etch is also important to proper function of the plate. Etching the plate just after it's loaded into the printing press gives the operator a prime opportunity to wipe the plate clean of any dust or debris that may interrupt the printing process. Small particles within the printing unit can cause a multitude of problems. A quick wipe after loading can save an operator an afternoon of headaches.
Plate etch has several uses, the first and most important of which is to pre-wet and sensitize the plate. Etch will fully wet the plate and cause the non-image area to become hydrophillic, or water loving, and causing the image area to become hydrophobic, or water repulsive. The second use of plate etch is to simply clean the plate. Sometimes between the time that a plate is made and the time that the plate is used on press it can be exposed to dust and random particles that can cause problems in the printing process. Etching the plate is a great way to give your plate a wet wipe down that will remove any dust and debris from the surface and provide a problem free press run.