Ablation is a general term that refers to the removal of material from the surface of an object by vaporization, chipping, or any other erosive processes. In prepress, ablation is a technology that is used in some output systems:
- Ablation can be used in computer-to-plate and direct-to-press systems to image plates by vaporizing or blasting away a part of the emulsion, typically with a thermal laser. A number of chemical-free or process-free CtP plates rely on this technology.
- In some ablation based systems the plate emulsion that is ablated is washed from the surface of the plate before it is used for printing at the press.
- With controlled ablation plates it is the fountain solution at the press that loosens the debris from the plate.
- With some ablation based CtP systems, the ablative technology can also be used to generate proofs.
- Ablation can also be an unwanted side effect from the use of laser technology. With all thermal CtP systems, some unwanted ablation occurs. In many system a series of filters minimizes the health risk for operators.